AF447 [Archive] - Page 14

SaturnV

8th Jul 2009, 01:49

xcitation, look no further than the performance of Dakar.

At 1 h 46, the DAKAR controller asked the ATLANTICO controller for further information regarding flight AF447 since he had no flight plan. The ATLANTICO controller provided the following elements: A332, from SBGL to LFPG, SELCAL: CPHQ.

The DAKAR OCEANIC Regional Control Centre created the flight plan and activated it. The result of this was to generate a virtual flight following the planned trajectory in the DAKAR FIR between TASIL and POMAT. There was no radio contact between AF447 and DAKAR, nor any ADS-C connection. . The flight remained virtual.....

At 2 h 47 min 00 s, the DAKAR controller coordinated flight AF447 by telephone (ATS/DS) with the SAL controller (Cape Verde) with the following information: passing the POMAT point (leaving the DAKAR FIR) estimated at 3 h 45, FL350, Mach 0.82.

At 2 h 48 min 07 s, the DAKAR controller told the SAL controller that flight AF447 had not yet established contact with him. [AF447 was to enter the Dakar FIR at Tasil at 0220.]

At 3 h 54 min 30 s, the SAL controller called the DAKAR controller by telephone (ATS/DS) to confirm the estimated time for passing the POMAT point. The latter confirmed that POMAT was estimated at 3 h 45. The DAKAR controller stated that the crew of flight AF447 had not contacted him to correct its estimate. The SAL controller replied that the estimate was
probably later. He asked the DAKAR controller if there was any change. The DAKAR controller then said that he was going to try to contact flight AF447. [The DAKAR controller apparently makes no effort to contact AF 447.]

At 4 h 07 min 4 s, the SAL controller requested confirmation of the flight AF447 estimate. The DAKAR controller confirmed again that POMAT was estimated at 3 h 45. The SAL controller pointed out that it was 4 h 8 and that the estimate was not correct. [B]The DAKAR controller recalled that contact had not been established with flight AF447. The SAL controller stated that he had identified flight AF459 on his radar whereas its estimate was later than that of flight AF447. The SAL controller said that he thought that the POMAT estimate was later, at 4 h 29 or 4 h 30. The Dakar controller told the SAL controller that he would call him back.

At 4 h 11 min 53 s, the DAKAR controller asked flight AF459 to contact flight AF447. At 4 h 20 min 27 s, the crew of AF459 informed the DAKAR controller that they were passing point POMAT at FL370. They had not succeed in contacting flight AF447 and said that they had sent a message to Air France so that the airline should try to contact flight AF447. [This is 2 hours after AF447 should have entered Dakar FIR,]

At 4 h 21 min 52s, the DAKAR controller asked the ATLANTICO controller to confirm that flight AF447 had passed TASIL at 2 h 20 at FL350. The ATLANTICO controller confirmed that TASIL was estimated at 2 h 20 but that no contact had been made.

At 4 h 18, the crew of flight AF459 sent a message to Air France so that the airline should try to contact flight AF447. At 4 h 24, Air France asked flight AF447 by ACARS to contact DAKAR OCEANIC

At 4 h 37 min 7 s, the DAKAR controller asked the SAL controller if he had still not been able to contact flight AF447 and informed him that, according to the ATLANTICO controller, the flight should have left the FIR at 2 h 20 and consequently the POMAT estimate should be 3 h 45.

At 4 h 39 min 42 s, the DAKAR controller asked the ATLANTICO controller to confirm that he had not had contact with flight AF447. The latter replied that he had not had contact at TASIL but that the first contact was at INTOL at 1 h 33. The DAKAR controller told the ATLANTICO controller that SAL had not established contact either.

.......

At 5 h 01 min 34 s, the DAKAR controller asked the CANARIAS controller if he was in contact with AF447. The latter replied that he had no information.

At 5 h 09 min 15 s, the ATLANTICO controller asked the DAKAR controller if he had any news of flight AF447. The DAKAR controller replied that he hadn’t and then the ATLANTICO controller requested confirmation that the flight was already in the SAL FIR. The DAKAR controller replied: "yes, no worry". He also confirmed that SAL had not established contact with flight AF447.

At 5 h 50, after several unsuccessful attempts to obtain information on flight AF447, Air France contacted the SARSAT (Search and Rescue Satellite Aided Tracking) centre. The latter had not detected any beacon transmission. Acting upon the advice of SARSAT, Air France contacted the Cinq Mars La Pile Regional Control Centre.

JD-EE

8th Jul 2009, 01:52

Will Fraser, I am not a wild eyed liability lawyer trying to drum up business. Why are you trying to sound like one rather than try to knock down the silly theories bouncing around here? I rather belatedly put on my engineering hat and started looking critical at the data being presented. It is WAY WAY premature to say that the data favors any given conclusion or conspiracy theory or other nonsense.

The ABSOLUTE furthest in that direction I am willing to go is that both the Brazilians and the French had some thought for the deceased and tried to avoid the circus that will happen after the autopsy reports are revealed to the public. And that's only within the realm of possible. It's not required to meet the facts as presented.

JD-EE
(I bet this gets pulled but I just had to vent.... Sorry folks.)

WhyIsThereAir

8th Jul 2009, 01:57

> And how is the acars still transmitting in a flat spin?

Do you still have AC 1 bus? If so, it can still transmit. If not, then no, it can't transmit.

If we're absolutely sure that AC 1 is dead in a flat spin, then we know that a flat spin can't be entered until the end of 0214. If we aren't sure, then maybe it can be entered earlier.

If a flat spin is incompatable with ACARS transmission, and we still believe that Bad Things(tm) happened around 0210-0211, then the Bad Things must not have included a flat spin.

singpilot

8th Jul 2009, 02:01

JD-EE

8th Jul 2009, 02:26

Art-Deco,

I've remarked in the past that the Inmarsat satellites and protocols are designed to work well within a deluge. I dug into references (the ITT handbook) and looked at the charts. Rain attenuation at Inmarsat frequencies is a bit under 2dB per km in a 25mm/hour rain storm at sea level. So in the very middle of a storm at low altitude the Inmarsat communications probably can become lost, at sea level. At FL350 there is less rain and less distance through it. For rain attenuation to be a factor the plane would have had to have already descended well down into the storm.

That's another useful data point. I am guessing the point where a loss due to rain becomes feasible to consider is maybe 15,000 feet give or take some.

JD-EE

JD-EE

8th Jul 2009, 02:38

Will Fraser, physicists and engineers seldom employ the word deceleration in my experience, as an engineer, unless talking to lay persons. A deceleration is simply a negative acceleration. Hitting the water imparts a (very) high negative rate of acceleration.

Please give it a rest. You can't seem to tell the difference between facts that can be checked against evidence made available and rumors leaked by unauthorized people wanting their moment of fame. If you can PROVE your contentions about the Brazilian leaks being facts, then do so. Otherwise, please drop it. The facts so far pulled from reports suggests that the plane did not magically transport itself backwards tens of kilometers along its path and then fall apart in the air. And no other scenario of break up in the air seems to fit where the plane could possibly have been and breakup in the air as you insist. It must have been coming down very fast with a pull up attempt right at the bitter end to support takata's data, the timing data derivable from the ACARS, and the apparent condition of the plane.

It would be nice to know the condition of the passengers, too. A cultural and communications snafu got in the way of BEA getting the autopsy reports. And it had a deadline by law for issuing the report while they were still in the field trying to collect what evidence they could. They were too busy to sit down a please everybody with a very complete report. And they were not required to present any conclusions at all. That they did vouchsafe us with an opinion is stepping beyond the minimum requirements of their charter.

JD-EE

ClippedCub

8th Jul 2009, 02:50

unless flat spin includes considerable motion in a constant direction after the spin is entered.

Translation along the earth axis coordinate system would have been at the wind velocity.

Not claiming a flat spin from altitude, or a flat spin at all, as there are other scenarios. One item to note, if someone can line up the ACARS pieces, is that pitot's are only good for small alphas. On the order of 15 degrees. A flat spin would produce alphas much higher, with rotation, generating a split among all three pitots. If a flat spin is suspected as producing the ASI splits, then it would be left to determine the chances an experienced crew would need to enter the spin in CB turbulence at altitude. Keep in mind that an aircraft at high alpha translates AOA to sideslip with wing rolloff. Two things are needed for spin entry, stall and sideslip.

Will Fraser

8th Jul 2009, 03:02

JD-EE

I have not once used the word deceleration. There is nothing to desist from. I have experience with the FAA and deliberative investigative authorities. I have no agenda, I believe everything I write. My lament is for a truly objective investigation. What started my displeasure was the inability of the French and the Brazilians to put any concerted effort together to collaborate. If I'm wrong, and there was free and active teamwork between the two, I will be the first to acknowledge it.

I am at this moment reading and translating the report from the French.
Please don't tutor me in Physics.

You are putting so many words on my plate that I never wrote. For one, I didn't say the a/c wasn't intact at impact, I criticised the BEA for concluding that it was, there is a difference. I am not pushing any theory, I continue to say there is virtually no evidence at all. My only surmise is I think consistent with prior history and reasonable interpretation of conditions based on my knowledge of them.
I think it may be you who is ahead of himself.

Regards JDEE

Will

Mad (Flt) Scientist

8th Jul 2009, 03:04

The concept of the descent of AF447 troubles me.

Anyone who has brought a 208 ton aircraft from altitude (normal, normal, normal) knows how 'difficult' it is to do when heavy. The aircraft will VERY happily accel to MMax with very slight pitchover. From FL350 to surface is 'normally' 25 minutes (powered), clean, and with unrestricted clearance. Gliding, under control as described, 15-ish minutes. Emergency dive, spoilers, (loss of pressurization) maybe 10 minutes (Regs) to 10000, then who knows to surface.

Throw in CB activity, mod to extreme turbulence, nightime, surprise, inattention, one or more failed engines, reversion to some unknown control law, and how long will that take?

Who knows. After a high altitude upset. Geez, maybe speed of a rock from 7 miles up.

My point is that a LOT of attention needs to normally be paid to keep the speed under control in a descent.

These modern designs are so clean, they accel going downhill at the drop of a hat.

I believe there is evidence (and its been posted fairly recently too) that a transport category aircraft in departed flight (stalled condition or similar) descends at a very high rate. While the modern airliner is indeed a slick, low-drag design in normal flight, with a stalled wing the drag is very much higher - perhaps orders of magnitude higher, in fact. IF AF447 had departed controlled flight at altitude into a stall (or spin as some have suggested) then a substantial rate of descent is entirely reasonable.

flyingchanges

8th Jul 2009, 03:12

Yes, but is not the acars satcom based, and if so, how is is going to stay stabilized during said flat spin, or any departure from controlled flight for that matter?

ArthurBorges

8th Jul 2009, 03:36

"normal flight attitude" smells to me like the best equivalent for "ligne de vol" in the BEA report.

In addition, one translation of "accélération" is "G"; thus "avec forte accélération" becomes "with high G forces". Source for this is Dassault's house dictionary: Lexique bilingue (http://www.dassault-aviation.com/services/fr/transverse/lexique-bilingue.html?langue=fr&cHash=e3acca8b80). Members may want to rummage through other equivalents for the term.

Nonetheless, Harry Mann is convincing with:

Airplane is travelling down. It makes contact with the water which stops the fall. This causes upward acceleration (possibly to a zero vertical speed).

Strong vertical acceleration means a strong CHANGE in the vertical component of the velocity. It doesn't necessarily mean anything beyond that.

Hope this helps.

JD-EE

8th Jul 2009, 03:37

flyingchanges asked, "And how is the acars still transmitting in a flat spin?"

I contend that as long as the plane was not on emergency power ACARS had the capability to transmit and reach the satellite unless it was really in the middle of a Biblical deluge.

If you are worried about antenna aiming draw an airplane, any old outline sketch will do. The antenna is a 6dB gain model relative to an antenna that radiates identically in all directions. A gentleman named Poynting observed that if you draw a sphere around a transmitter antenna you cannot get more power out of that sphere than you put into it. With that in mind you get gain by sacrificing portions of the sphere to enhance other portions. The first thing most antennas in practical installations sacrifice is "the other hemisphere". If they are to look up they lose down. If they are to look down they lose up. That gives a cool 100% power boost, 3dB. If they cut the angle down further, say from being a section of a sphere from 0 to 90 degrees from vertical and it becomes oh maybe 60 degrees from vertical to pure vertical the gain boosts another (very) roughly 3dB. If I require less than 1 to 2 dB of loss from peak performance I've been figuring on 40 degrees and the Atlantic satellite in use was 10 degrees to the East.

Thus if the plane's attitude was within 20 to 30 degrees of horizontal and it had power for ACARS then ACARS messages could be sent.

There is question of whether or not there really were. Although to my untutored eyes they seem to cut off almost mid-sentence, so to speak. There looks like there should have been more story to tell.

Rain has been mentioned for the short signal loss that happened. That might, also, have been the plane coming down to a level where there was enough air bite to execute a turn or other attitude changing maneuver to recover from uncontrolled flight. That might also explain the loss.

The ACARS signal does give us some data to estimate, only estimate, the condition of the plane through 0215 as being roughly horizontal and with power. After that it was controlled or uncontrolled flight without power, most likely. We don't know for sure. But, this limits the range of guesses for what might have happened.

JD-EE

ArthurBorges

8th Jul 2009, 03:42

What started my displeasure was the inability of the French and the Brazilians to put any concerted effort together to collaborate.
PARIS, July 7 (Xinhua) -- French President Nicolas Sarkozy and his Brazilian counterpart Luiz Inacio Lula da Silva discussed hereon Tuesday the cooperation between the two countries on the search operation and investigation following the June 1 air crash of Air France Flight 447 en route from Rio de Janeiro to Paris. "There is a black hole. This is not normal," Sarkozy said at a joint news conference with Lula.
Sarkozy said Foreign Minister Bernard Kouchner and Cooperation Minister Alain Joyandet were headed to Senegal to see "how we can avoid this black hole, this void in communications."

You can see the rest of the article at

France, Brazil discuss cooperation following plane crash_English_Xinhua (http://news.xinhuanet.com/english/2009-07/08/content_11670057.htm)

Dare I anticipate exasperation among members here who read all the way to the end where it says:

Lula rejected French claims that they were denied access to the autopsies. "There is nothing to hide," he said. Sarkozy and Lula also called for "a more democratic world order, one founded in greater solidarity and justice," to give emerging economies more say in international finance and justice.
Lula insisted that now be the right time for a South American country to host its first Olympics.

With a gold, silver and bronze for the first three passengers out the emergency exits?

Lightning6

8th Jul 2009, 03:51

Just a point of interest from NASA:-

July 7, 2009

RELEASE : 09-154

NASA Research to Help Aircraft Avoid Ocean Storms, Turbulence

WASHINGTON -- NASA is funding the development of a prototype system to provide aircraft with updates about severe storms and turbulence as they fly across remote ocean regions.

Scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., in partnership with colleagues at the University of Wisconsin, are developing a system that combines satellite data and computer weather models with cutting-edge artificial intelligence techniques. The goal is to identify and predict rapidly evolving storms and other potential areas of turbulence.

"Turbulence is the leading cause of injuries in commercial aviation," said John Haynes, program manager in the Earth Science Division's Applied Sciences Program at NASA Headquarters in Washington. "This new work to detect the likelihood of turbulence associated with oceanic storms using key space-based indicators is of crucial importance to pilots."

The system is designed to help guide pilots away from intense weather. A variety of NASA spacecraft observations are being used in the project, including data from NASA's Terra, Aqua, Tropical Rainfall Measuring Mission, CloudSat and CALIPSO satellites.

The prototype system will identify areas of turbulence in clear regions of the atmosphere as well as within storms. It is on track for testing next year. Pilots on selected transoceanic routes will receive real-time turbulence updates and provide feedback. When the system is finalized, it will provide pilots and ground-based controllers with text-based maps and graphical displays showing regions of likely turbulence and storms.

"Pilots currently have little weather information as they fly over remote stretches of the ocean, which is where some of the worst turbulence occurs," said scientist John Williams, one of the project leads at NCAR. "Providing pilots with at least an approximate picture of developing storms could help guide them safely around areas of potentially severe turbulence."

NCAR currently provides real-time maps of turbulence at various altitudes over the continental United States. Williams and his colleagues are building on this expertise to identify turbulence over oceans. The team has created global maps of clear air turbulence based on global computer weather models that include winds and other instabilities in the atmosphere. Drawing on satellite images of storms, the scientists also have created global views of the tops of storm clouds. Higher cloud tops often are associated with more intense storms, although not necessarily with turbulence.

The next step is to pinpoint areas of possible turbulence within and around intense storms. The team will study correlations between storms and turbulence over the continental United States, where weather is closely observed, and then infer patterns of turbulence for storms over oceans.

In addition to providing aircraft and ground controllers with up-to-the-minute maps of turbulence, the NCAR team is turning to an artificial intelligence technique, known as "random forests," to provide short-term forecasts.

Random forests, which have proven useful for forecasting thunderstorms over land, consist of many decision trees that each cast a yes-or-no "vote" on crucial elements of the storm at future points in time and space. This enables scientists to forecast the movement and strength of the storm during the next few hours.

"Our goal is to give pilots a regularly updated picture of the likely storms ahead as they fly over the ocean, so they can take action to minimize turbulence and keep their aircraft out of danger," explained NCAR scientist Cathy Kessinger, a project team member.

The NCAR project is funded by NASA's Applied Sciences Program, which seeks to translate NASA's investment in Earth observations into applications that address real problems. The program and its partners are working to bridge the gap between research results and operational aviation weather products in such areas as in-flight icing, convective weather, turbulence, volcanic ash and space weather.

For images related to this turbulence prototype system, visit:

NASA - NASA Research to Help Aircraft Avoid Ocean Storms, Turbulence (http://www.nasa.gov/topics/earth/features/turbulence.html)

ttcse

8th Jul 2009, 04:36

Clipped,
Two things are needed for spin entry, stall and sideslip.Just to review, 3 1/2 other things can possibly replace the sideslip.
1) When close to the critical AOA, dropping an aileron (say in rapid response to the start of roll-off on one side) effectively increases the AOA in the region of the aileron and could stall that region.
2)When close to the critical AOA, having a some upward gust applied to the outer wing section on one side, causing it to exceed critical AOA.
3)When close to the critical AOA, making a smaller radius turn so that the inside wingtip is flying more slowly that the outer wingtip and effectively causing a greater AOA on the inside wingtip (same vertical vector amount, less horizontal). More an issue with long-winged aircraft.

and 1/2) The typical spin entry we're all aware of, when close to the AOA kicking in rudder for some reason. With the A330 you can substitute differential engine thrust for the rudder. While it may or not slip sideways overall, that's not the problem. It's the yawing so that the inside wingtip flies more slowly or even backwards relative to the other tip. Due to vertical vs horizontal flight vectors of the tips, the inside tip goes critical and the other away from critical.

I'm sure you knew this.

vapilot2004

8th Jul 2009, 05:24

JD-EE

There are a few statements in the BEA report that are questionable to say the least. No matter. I would like to better understand your posit that the aircraft's engines were not turning and burning?

JD-EE

8th Jul 2009, 05:42

vapilot2004 said, "There are a few statements in the BEA report that are questionable to say the least. No matter. I would like to better understand your posit that the aircraft's engines were not turning and burning?"

As far as can be determined nothing that was not supposed to have flame active in, on, or near it had flame in, on or near it.

A recent message raised doubts about which busses have to go down to kill ACARS. I'd had the understanding that if the engines were turning, properly, that ACARS had power. The plane was sufficiently "together" for ACARS to work through the last ACARS transaction and acknowledgement cycle. That puts the plane in one piece, approximately horizontal, and with power at that time. Loss of power, a relatively large attitude abberation, loss of source of ACARS messages, or simply there were no more ACARS messages to send are the only things that come to mind that would stop them. That latter option sounds like a lower probability than the other three for any long term interruption of ACARS messages while the plane was still under power, horizontal, and in one piece.

My contention is that takata's work coupled with "where could the plane have gotten to before signals ceased" will tell is something important about what the plane did subsequent to the end of the ACARS messages. We can test the flat spin scenario, the dive to try to restart scenario, and all the other scenarios against it. That trims out a lot of bad ones, does it not? The current data very strongly suggests the plane did not stop in mid air and start falling at any of the times of the ACARS messages, for example. The currents would have carried the bodies and debris to completely different positions in those scenarios.

Once we have a class of scenarios that fit these two data sets we add a third and start eliminating what does not fit. We keep adding data sets as they appear and eliminating the scenarios that don't fit. In the end, if we have new data fed in, we may arrive at a solution without the suspected political biases. For fact checking the final report, whether or not it reaches any conclusions, the only original data we cannot get for ourselves is the on site visual impressions from the condition of the debris.

Peel away what is impossible. Whatever is left becomes probable.

JD-EE

LeandroSecundo

8th Jul 2009, 05:45

Hi,

NASA Research to Help Aircraft Avoid Ocean Storms, Turbulence

Ironically .. seem's all the scientifics and people linked to aviation safety discovered suddenly ocean storms and turbulences existence after the AF447 event ...
Sure it's some bussines and some bucks to make there.

Bye.

jmmilner

8th Jul 2009, 06:05

Ironically .. seem's all the scientifics and people linked to aviation safety discovered suddenly ocean storms and turbulences existence after the AF447 event ...
Sure it's some bussines and some bucks to make there.In the U.S. it has been a common political tactic to dismiss as wasteful almost any spending for what appears to our political leaders as abstract scientific research. When a large number of people suddenly die without apparent reason, the political figures hold hearing to deflect the blame and sometimes even authorize spending to find a cause. If it then happens again they can blame the scientific community for not having come up with the answer.

Is this not how it would be handled in Spain?

WhyIsThereAir

8th Jul 2009, 06:08

Ironically .. seem's all the scientifics and people linked to aviation safety discovered suddenly ocean storms and turbulences existence after the AF447 event ...
Sure it's some bussines and some bucks to make there.

I'm sure there is some of that going on. But most of that sort of thing would be people proposing new ideas they will happily research if they are provided with lots of money.

I think this is the other side of that coin.
The evidence is they have been slogging away at this for years and probably spending half their time trying to avoid getting their funding cut because implementation takes more than 3 months. They see people suddenly worried about thunder storms and flying things, and quickly send out a press release saying 'Hey! We're working on fixing that!" They can then use the press clippings when the question of funding again comes up in another 2 months. Now, whether they will ever come up with anything useful is another quesiton.

HazelNuts39

8th Jul 2009, 07:42

Re: #3243 (JD-EE)

Thanks for replying.

Please note that my post gives turning parameters as a function of angle of bank (angle of roll if you like) - not angle of attack.

Regards,
HN39

Professorrah

8th Jul 2009, 08:16

And how is the acars still transmitting in a flat spin?

Good question. The Antenna used for the ACARS transmission is a low profile electronically steerable array.
On system power up, the antenna sweeps through 360o looking for a syncronisation signal and locks to this at the acquisition bearing. The system is then able to track this sycronisation signal on ground and in-flight and If looses lock,which can inevitably happens for a number of reasons, it then enters the re-acquisition mode and re-starts the sweep. This however would not be fast enough, or designed to be able to obtain and re-acquire lock if the aircraft was in a flat spin - therefore would loose the sycronisation path with the Satellite and loss of ACARS transmission.

ARFOR

8th Jul 2009, 08:21

PJ (& others) I have a couple of supplementary Q’s

- If one engine (either one) failed, at what shaft (% RPM) would the associated GEN trip out? And;
- Notwithstanding the above, following a single engine (either one) failure, would AC1 remain energized by the other power plant? If yes;
- Following the inevitable ECAM/s, would ACARS output message/s?

On a similar but different subject, at FL350 & M.82:-

- Following an asymmetric failure (whilst in ALTN 2), how promptly would the PF need to get rudder in to avoid yaw induced roll?

FanAviation

8th Jul 2009, 08:26

Will Frazer/Willy B. I'm afraid there might be a gross misunderstanding of the warning foreword (Avertissement p.1)

"This document has been prepared on the basis of the the first elements gathered during the investigation, without any analysis and even - given the continuing absence of wreckage, the flight recorders, radar tracks and direct testimony - without any description of the circumstances of the accident."

This means the report is made ONLY with the information gathered during the investigation.
- There was no analysis of the data coming from FDR/VCR (available to the investigation team) as they have not even been found
- There was no direct testimony (available to the investigation team) as nobody was there to tell what they have seen.
- There was even no wreckage and no radar track available.

This is clearly stating (to a french speaking person):
This report is not the final one (because it is using only the first elements found, other might be found at a later stage) and, we have nothing available to help us understand, only what was found, with only our eyes to see it and our brains to try to understand what could have caused what we see (= we are the first ones to try to figure out what happened and we know nothing of the major facts: no wreckage to see, no analysis of the FR done by experts because there is no FR available yet, and nobody has seen the crash...).
It is a very humble statement, they know -and they are writing it without any ambiguity- the finding of the wreckage, the finding and analysis of the FR data might completely change the picture.
Again I hope this helps...

ITman

8th Jul 2009, 08:51

You may get some answers from this very recent incident...

NTSB: Airbus A330 Experienced An 'Airspeed Anomaly' Northwest Flight Crew In Japan Noted Airspeed Fluctuations

The NTSB has released a preliminary
finding in an incident involving a Northwest Airlines Airbus A330
on a flight in Japan last month in which the onboard computers
switched off the aircraft's autopilot possibly due in part to
inconsistent airspeed indications.

The report reads:

NORTHWEST AIRLINES INC
Incident occurred Tuesday, June 23, 2009 in Kagoshima, Japan
Aircraft: AIRBUS A330-323, registration: N805NW
Injuries: 217 Uninjured.

This is preliminary information, subject to change, and may
contain errors. Any errors in this report will be corrected when
the final report has been completed.

On June 23, 2009, at 0303 UTC, an Airbus
330-323, U.S. registration N805NW, operated by Northwest Airlines
as flight 8 from Hong Kong, China, to Tokyo, Japan, experienced an
airspeed anomaly while in cruise flight at FL390 approximately 50
miles southwest of Kagoshima, Japan. The crew reported that they
were in normal cruise at FL390 and in visual conditions with some
convective weather displayed on radar about 25 miles north of
track, with thin cirrus clouds ahead.

After entering the cirrus and moderate precipitation and
turbulence, the crew observed, and FDR confirms, the autopilot and
autothrust switch off, and the aircraft switched to Alternate Law.
The master caution and warning messages were activated. The crew
followed flight manual procedures and the autopilot and normal law
returned in about one minute, however the event quickly repeated
itself, lasting for about 2 minutes. The crew turned the airplane
60 degrees off course to exit the weather as soon as the anomalous
indications were observed. The autopilot, autothrust and other
controls returned to functioning, but the airplane remained in
alternate law for the rest of the flight.

The crew observed, and FDR confirms, large airspeed
fluctuations, small altitude fluctuations, and an overspeed alert.
The flight continued to Tokyo, Narita airport and landed with no
damage or injuries to the 9 crew and 208 passengers on board.

The incident occurred in Japanese airspace, and the
investigation was delegated to NTSB by the Japanese Transportation
Safety Board, who assigned an Accredited Representative to the
investigation.
FMI: National Transportation Safety Board (http://www.ntsb.gov)

WhyIsThereAir

8th Jul 2009, 09:04

> therefore would loose the sycronisation path with the Satellite and loss of ACARS transmission.

While quite possible, not necessarily in this case. The target satellite was effectively directly overhead, and the antenna beam angle is around 60 degrees. So in a flat spin that is horizontal there should only be a few degrees of wobble in the bird position, and that probably wouldn't even be detectable as a gain change.

If the link was lost for other reasons, I suspect that it might be recovered moderately easily since the bird wouldn't be moving much in terms of antenna steering angle.

Dr Brian Evans

8th Jul 2009, 09:48

barstow

8th Jul 2009, 10:05

The link to the satellite might be broken if the a/c was rotating (spinning) The antenna on the a/c might not be able to keep up with the changes in signal polarisation caused by the rotation of the aircraft. Such a vulnerability is dependant on the type of polarisation used. Perhaps JD-EE can advise.

Can I just pre-empt JD-EE's response by saying, no the aircraft would have to be spinning several orders of magnitudes faster than is possible to upset the signal ploarization.

JD-EE

8th Jul 2009, 10:39

barstow, that is right, in part. The communications path and antennas, of course, use circular polarization. So changing orientation cannot upset the polarization. With circular polarization you cannot get cross polarization. The Inmarsat people used that trick to good advantage.

JD-EE ;)

HarryMann

8th Jul 2009, 10:47

That's another useful data point. I am guessing the point where a loss due to rain becomes feasible to consider is maybe 15,000 feet give or take some... and maybe a very good one, with the limited points available after 02:10
Could also be due to pitch or roll angle if momentarily exceeded those limits discussed above

Another data point that has been lost way back when, to add to the VS (& possibly tailcone) is the single spoiler that was found.

Admittedly a very small and dubious one, but nevertheless, bearing in mind the suggested impact mode, could this really have been broken off (apparently by a forwards force & upwards bending moment) with the assocaited flaps in the retracted position?

FAStoat

8th Jul 2009, 11:43

When you depart an Aircraft from High Altitude unintentionally,or in an intentional Training Sortie,the Aircraft does NOT enter a flat spin,unless deliberately induced,although it can seem like that from inside the cockpit.It actually loses lift from different points along the wing and stabiliser,so enters a tumble of pitch yaw roll oscillation.If you used to watch "War in the Air" films of battle damaged B17s and B24s entering spins,these are rather more uncontrolled tumbles than actual spins.A flat spin is rather hard to get into especially in a large aeroplane,but a departure tumble can happen ,especially when flying through extreme Up and Downdrafts in Cbs.We used to do that in Training when deliberately exceeding Crit mach to show departure recovery.,albeit many years ago.Incidentally KLM used to use 2 Harvard Trainers up to the 70s or maybe longer to give Long Haul Captains Spin awareness Training,as Crews had not seen the manoevre for so long since initial Flight Training.I believe the Pilots Union had it stopped as it caused much trepidation to older Captains.To experience the like in a 200 Ton Airliner beggars belief.let alone trying to recover with normal controls,let alone a side stick in "Alternate Law"!!!

syseng68k

8th Jul 2009, 12:14

Admittedly a very small and dubious one, but nevertheless, bearing in mind the suggested impact mode, could this really have been broken off (apparently by a forwards force & upwards bending moment) with the assocaited flaps in the retracted position?

I asked this question some time ago and got what seemed like a fair answer in that if the tail impacted first, it could have disintegrated leaving the vs free to float away. The only other possibility is that the vs separated in flight at some stage, but does the recovery position in relation to the remainder of material recovered support this view ?.

I just can’t accept that a perfectly serviceable aircraft would break up in mid air unless airframe stress limits were exceeded by (probably) quite a wide margin. The only things remaining, assuming the pilots were not practicing aerobatics, are extreme weather conditions or massive systems failure. The acars evidence, really doesn’t support the latter, looking more like the result of what was happening, rather than the cause.

I don’t take sides re climate change, (too much politics, not enough science) but assume for a moment that climate change is in process and that more severe weather is one of the byproducts. Could it be that what used to be considered extreme weather conditions are now more commonplace and extremes are now more so ?. One snippet of evidence in context that might support this view is the increased incidence of pitot icing and failure in the last few years. Has this always been a problem, the result of changed flying practices, or what ?. Pitot probe design hasn’t changed much in decades, so why are they failing in the same way now ?…

HarryMann

8th Jul 2009, 12:21

My point was more about thinking through the implications of what little external structure has been found... whether it supports the BEAs view on the state of the a/c and mode of impact... re the spoiler which has been given little attention, undertsandably so perhaps.

The implication for it it to be broken off in the way it appears might be:

The flaps were down given underside access to water impact forces in a rightside up impact
It was out, and that wing sinking rapidly but backwards
The a/c completely tumbled with it out (least likely)

HazelNuts39

8th Jul 2009, 12:40

re: #3245 (Hyperveloce)

Pretty accurate guess Hyperveloce, my CASIO shows 4431 ft

regards,
HN39

ClippedCub

8th Jul 2009, 13:05

Just to review, 3 1/2 other things can possibly replace the sideslip.
1) When close to the critical AOA, dropping an aileron (say in rapid response to the start of roll-off on one side) effectively increases the AOA in the region of the aileron and could stall that region.
2)When close to the critical AOA, having a some upward gust applied to the outer wing section on one side, causing it to exceed critical AOA.
3)When close to the critical AOA, making a smaller radius turn so that the inside wingtip is flying more slowly that the outer wingtip and effectively causing a greater AOA on the inside wingtip (same vertical vector amount, less horizontal). More an issue with long-winged aircraft.

and 1/2) The typical spin entry we're all aware of, when close to the AOA kicking in rudder for some reason. With the A330 you can substitute differential engine thrust for the rudder. While it may or not slip sideways overall, that's not the problem. It's the yawing so that the inside wingtip flies more slowly or even backwards relative to the other tip. Due to vertical vs horizontal flight vectors of the tips, the inside tip goes critical and the other away from critical.

Your first three points are confusing roll with sideslip. Coordinated roll will not invoke a spin by itself, the conversion of aoa to yaw angle with roll off creates the effect. Your first three points explain roll-off.

Your 1/2 point is what is taught in ppl straight wing trainers. While this applies to the A330, it's effect is minor compared to the effect of unsweeping the upwind wing and increasing sweep on the downward wing. This sweep effect due to sideslip is easy to visualize. Draw an A330 planform on paper with a vector coming from 20 degrees off the nose. Tilt the paper till the vector is vertical. Observe that upwind wing gets longer and is unswept. The downwind wing gets shorter with increased sweep.

Also understand that CLmax changes with the cosine of the sweep.

Hope this helps. And thanks for demonstrating that stall and sideslip are the two components needed for spin entry.

Edit: The 1/2 point also explains roll-off. So all 3.5 points don't replace sideslip, but do explain how a roll-off can occur which does induce sideslip once roll-off occurs.

Hyperveloce

8th Jul 2009, 13:08

-for the satcom/ACARS, we would need the real radiation pattern of the antenna (polar nulls ?) and some data about the link budget and the signal modulation/processing to assess whether the weather conditions and/or an unusual attitude of the airframe may have weakened and/or masked the satbeam to a point of disruption. there wasn't any electrical activity detected from satellite imagery, but the flight LH507 which preceded AF 447 by 20 mn was subjected to St Elmo's fires on the left-hand side of the cockpit: possible sources of interferences here, with a band around 1.5 GHz or comms ? (don't think so but I may be wrong). also wonder about the functional temperature range of the antenna.
-for the loss of control at high altitude, I was frightened by the rapidity of the loss of control of the Adams Air plane: the crew attention was focussed on a failed IRU, did the AP disengage and let a slight bank to progress ? (in the Qantas case, when the AP 1st disengage, it allowed a slight altitude drift to unfold). between the banking alarms, the clicket sounds (30s) and the first prayers, it is a matter of 40-50s. :uhoh: (I now hear their prayers from times to times and the horrible aerodynamical noise, how can this be available on the web ? I do not understand).
Jeff

Hyperveloce

8th Jul 2009, 13:12

HazelNuts39

8th Jul 2009, 13:50

RE: #3248 (FanAviation)

I heartily support your observations except on one (very minor) point.

Quote:
Then it says "the plane has probably (vraisemblablement)) hit the surface of water in flight line ("with" but the word is missing here) a strong vertical acceleration"
/Unquote

In my opinion the word "with" is not missing but was incorrectly inserted in the english translation, and later in the Findings (french and english texts). The 'frenchman with a scientific background' was quite correct. Inserting the word "with" makes the "acceleration" part of the impact entry conditions, which it is not. Without the word "with", the statement correctly observes only that visual examination showed that the parts had been subjected to strong acceleration (caused by impact forces).

regards,
HW39 - newbie dutchman with engineering background

4nsicdoc

8th Jul 2009, 14:05

Actually, at equatorial water temperatures, say, 25deg. C and above, in saltwater, a body , if it sinks at all, can surface in less than 24 hours. Depends on exact temp, body fat, clothing, completeness of the remains, salinity. Water temp is the most important factor for 2 reasons. As water warms, at least above 0C, it expands, reducing its density. Also, warmth accelerates decomp and the attendant release of gasses.

Graybeard

8th Jul 2009, 14:14

NTSB on NW A330:
The crew observed, and FDR confirms, large airspeedfluctuations, small altitude fluctuations, and an overspeed alert.

Here's what the FO wrote in an email the day after:
... Entering the cloud tops we experienced just light to moderate turbulence. (The winds were around 30kts at altitude.) After about 15 sec. we encountered moderate rain. We thought it odd to have rain streaming up the windshield at this altitude and the sound of the plane getting pelted like an aluminum garage door. It got very warm and humid in the cockpit all of a sudden. Five seconds later the Captains, First Officers, and standby airspeed indicators rolled back to 60kts. The auto pilot and auto throttles disengaged. The Master Warning and Master Caution flashed, and the sounds of chirps and clicks letting us know these things were happening.

Jerry, the Capt. hand flew the plane on the shortest vector out of the rain. The airspeed indicators briefly came back but failed again. The failure lasted for THREE minutes. We flew the recommended 83%N1 power setting. When the airspeed indicators came back. we were within 5 knots of our desired speed. Everything returned to normal except for the computer logic controlling the plane. (We were in alternate law for the rest of the flight.)...

GB

syseng68k

8th Jul 2009, 14:26

My point was more about thinking through the implications of what little external structure has been found... whether it supports the BEAs view on the state of the a/c and mode of impact... re the spoiler which has been given little attention, understandably so perhaps.

Not qualified to comment on the aerodynamics, but you could get a good idea of force vector by looking at the remaining attachment points and or pivots, if you could find a high enough res photo. For example, hole elongation on a hinge point prior to pin shear.

Some of the attachment points looked fairly intact, iirc...

CharlieBrem

8th Jul 2009, 14:31

Eurocockpit, which has the inside track from Air France pilots, has just posted their first reaction to the BEA initial report
Eurocockpit - Accueil (http://www.eurocockpit.com/)

For the moment it's only in French. They promise an English version. But their point is that they suspect the BEA and Air France of being economical with the truth.

L'affaire du vol AF447 ne fait que commencer, et nous pouvons dès aujourd'hui annoncer qu'il sera très difficile de cacher la vérité.

Which means.... The case of AF447 has only just begun and we can from today announce that it will be very difficult to hide the truth...

Eurocockpit says that on June 5 -- four days after AF447 -- Air France modified the standing Airbus procedure for handling unreliable airspeed indications. The June 5 note told crews to ignore stall warnings and run the checklist before undertaking corrective action, says Eurocockpit. Perhaps the experts could explain the implications of that.

Gringobr

8th Jul 2009, 14:43

The water temperature in the search area was 30°C
If that seems high to you English etc, it was 2° N of the equator, and I am here in southern Brazil, 26°S and 27°C is quite common in summer:)

ttcse

8th Jul 2009, 14:55

ClippedHope this helps. And thanks for demonstrating that stall and sideslip are the two components needed for spin entry.
You are confusing side-effects with the essential requirements of spin entry and spins. And since like Dani, you wish to protect and retain your pre-existing mis-understandings I won't require you to change. Since this thread is about AF447 it would be inappropriate to sidetrack and give you flight instruction. I'll let my statement on spin entry stand, it is entirely accurate. Ignore if you wish. Hope that helped.

fyrefli

8th Jul 2009, 15:02

"normal flight attitude" smells to me like the best equivalent for "ligne de vol" in the BEA report.

I disagree strongly. In fact, I meant to edit my previous post on the subject to clarify that it almost certainly doesn't denote anything about either heading *or* attitude, simply that any horizontal motion was nose-first.

Will Fraser

8th Jul 2009, 15:18

FanAviation

It is tempting to send this as a mere PM, but I think it may be helpful for a few of us. My conclusions re: the report, have to do with its whole appearance, context, continuity and related elements of purpose. Fanaviation, I see your point clearly, and in a way I would defend the paper as you are. However, and this is very complicated to convey, there are some very subtle constructs at work here, and without your understanding of the paper's purpose in all its iterations, your view of the actual product will be directed by perhaps said lack of understanding.
The mechanism at issue here transcends language, believe me. I apologize if I myself misunderstand your apparent defense of the Report.

Will

fyrefli

I agree with you. "attitude of flight" can be interchangeable with 'en ligne de vol'. As "heading" there is also evidence in the debris to support a claim of Horizontal travel at impact. That evidence was not addressed, and "forward flight" was left to be mysterious, as was any "rotation" of a/c at impact, which is also demonstrable in evidence, but was not so demonstrated. This report has the appearance of hit and miss reporting, some conclusions are offered, some hinted at, some treated differently, and therefore ignored. The jumbled nature of the paper is not evidence of the BEA's inability to write a conclusive and coherent preliminary statement, nor of the lack of time in which to prepare one.

Will

fyrefli

8th Jul 2009, 15:22

Will, I for one understand what you're getting at - again, perhaps I could have mentioned that in my previous post on the translation but, as a purely recreational pilot, didn't want to overstep the mods' boundaries.

HarryMann

8th Jul 2009, 15:28

syseng68k (http://www.pprune.org/members/302789-syseng68k)

If you read back a few hundred posts or so, there was already fairly clear evidence and discussion about the direction and forces required to break it off...

I am now (trying) to go one stage further, the subtlety of bringing it back into discussion after BEAs preliminary comments though, seems to keep getting lost....

HarryMann

8th Jul 2009, 15:35

Will, I for one understand what you're getting at

I think many of us do.... even though a large proportion don't fully subscribe or realise to do otherwise -at this stage - would be unwise.

Th facts were fairly simply and fully stated and one or two initial ideas on the crash impact itself based on their structural analysis of debris put forward.

PJ2

8th Jul 2009, 15:38

ARFOR;
- If one engine (either one) failed, at what shaft (% RPM) would the associated GEN trip out?
A quick review of the AOM does not provide an RPM. However, if I understand your point, you may be thinking that a windmilling engine may supply electrical power and that would not be the case as a windmilling high-pressure compressor section rotation at cruise speed is below the RPM required for electrical generation (The RR Trent would be around 12 to 15% if I recall correctly from the sim but someone with current experience may be able to confirm/correct this. I believe the gearcase is taken off the N3 but, frustratingly, the AOM doesn't tell us - the AOM NTK - need-to-know, description is about the level of, "the engine has 3 rotating sections with turbines attached...).- Notwithstanding the above, following a single engine (either one) failure, would AC1 remain energized by the other power plant? If yes;
- Following the inevitable ECAM/s, would ACARS output message/s?
Under normal (design) circumstances, all AC and DC busses remain powered; there is some load shedding, (galleys) in loss of generation.

As you say, the ECAM would display the failures and the required actions. FLR/WRN category messages would be generated and recorded by the FIDS, (Fault Isolation and Detection System), collated by the CMS (Central Maintenance System) and sent to the ACARS for maintenance action. In short, they would be a part of any transmitted messages.
- Following an asymmetric failure (whilst in ALTN 2), how promptly would the PF need to get rudder in to avoid yaw induced roll?It is entirely dependant upon yaw developed in the spectrum from idle thrust to takeoff/go-around power. An engine failure at idle thrust would not require any rudder at all; an engine at takeoff thrust requires an immediate response, and initially requires about 14deg of rudder, from which one backs off (after trimming out the yaw), depending upon the airplane's needs. In cruise, an engine failure would require an immediate but small application of rudder, (gently!). As with all high-altitude flight one must be careful with the use of controls because thin air provides so little damping effect. Providing rudder is used judiciously, roll-due-to-yaw is not a problem.

4nsicdoc

8th Jul 2009, 15:44

At 30 deg. C, the average specific gravity of saltwater is 1.022g/cc^3. That of the average human body is very close to 1.00., so, in those conditions, a body would be barely on the surface, at least until enough methane, hydrogen sulphide and trace mercaptins were generated to raise more of the body out of the water.

Will Fraser

8th Jul 2009, 15:48

HarryMann

I believe the spoiler is very important for what it can suggest. With Flaps 0, there is no airflow available to pop the spoiler out of its mounts. With any deployment, the area under the spoiler opens up and exposes the underside of the spoiler to some value of airflow. As with the Engines discussion (long in coming, I think), there is reason to entertain some configuration that at first blush might seem ridiculous, but perhaps not to pilots up against upset, uncontrollable a/c, and impact with the Ocean.

Will

captainflame

8th Jul 2009, 15:59

I understand how a lot of the threaders here, not being fluent in french (or have NIL notion of it at all) have difficulties understanding the BEA statement regarding the "probable" way the aircraft impacted the water.

Can you please trust the french speaking airmen here present, who KNOW both languages, especially the aeronautical terms, to translate what this means without having to submit other ludicrous attempts at google translating and other wikipedia electronic translations and so on, to get a CLUE !!

As stated previously, "en ligne de vol" means "flight attitude", which does mean attitude of the aircraft.
They mean it impacted flat, that's all.

Please don't ANY not french speaking person tell me this is not correct !!:ugh:

PJ2

8th Jul 2009, 16:02

Will;

For information only and not in response to notions posited, it is possible that hydraulic power would be available from a windmilling engine depending upon forward speed. 250kts Indicated would do it, 180kts maybe. However, high-demand services such as flaps would likely not operate or would be extremely slow. Also, the RAT (hydraulic power only - very low flow) requires 260kts for full (8.7KVA) emerg gen operation, otherwise loads are shed as output is reduced to 3.5KVA.

Will Fraser

8th Jul 2009, 16:08

captainflame

I understand your frustration and annoyance. By way of explanation, there is a difference between a definition of a term in any language, and what is meant by its use. Do you see this? This is not about what words mean, but what people mean in using them.

Your conclusion that "this is what they meant" is open to serious question. If that is not understood, then we will just have to agree to disagree.

Will

PJ2, noted, and thanks, as always

Mr Optimistic

8th Jul 2009, 16:34

Is the reverse view of the orange container here the back of the galley structure previously discussed?

More New Photos of AF447 Wreckage at Flightstory.net - Aviation Blog (http://blog.flightstory.net/1250/more-new-photos-of-af447-wreckage/)

If so, the impact looks to have been remarkably vertical and of (relatively) low intensity. That structure would be very weak in shear.

Hyperveloce

8th Jul 2009, 16:38

Hi there,
The following article may be of interest: SKYbrary - High Level Ice Crystal Icing (http://www.skybrary.aero/index.php/High_Level_Ice_Crystal_Icing)
This one can give clues about ice crystals observed (or not) by conventional E.M. weather onboard radars like the ones on airliners and by several Lidars
AMS Online Journals - Studying Altocumulus with Ice Virga Using Ground-Based Active and Passive Remote Sensors (http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0450(2004)043%3C0449%3ASAWIVU%3E2.0.CO%3B2&ct=1#I1520-0450-43-3-449-F10)
Seems that these dry crystals are difficult to detect using E.M. radars.
Jeff

syseng68k

8th Jul 2009, 16:43

If you read back a few hundred posts or so, there was already fairly clear evidence and discussion about the direction and forces required to break it off...

I am now (trying) to go one stage further, the subtlety of bringing it back into discussion after BEAs preliminary comments though, seems to keep getting lost....

I think I see what you are driving at: As with the vs, there does seem to be disagreement between the report and direction of travel required to sever the vs and / or spoiler, unless the impact vectors included speed opposite to direction of flight. Correct me if i'm misreading this, or you have a better explanation.

As an aside, some info and pics on spoiler manufacture which may be of interest:

Composite Spoilers Brake Airbus For Landing: COMPOSITESWORLD.COM (http://www.compositesworld.com/articles/composite-spoilers-brake-airbus-for-landing.aspx)

Graybeard

8th Jul 2009, 16:45

...Seems that these dry crystals are difficult to detect using E.M. radars.
Jeff

Yep, that's why the procedure to paint at the freezing level of the storm before getting close. That's covered in techlog.

GB

captainflame

8th Jul 2009, 16:48

Will,

Excatly right, it's what they mean.

I submit to you that a French speaking airman is able to tell anyone what the BEA means with this statement.

Whether you put it in doubt or not is another story !

Will Fraser

8th Jul 2009, 16:52

Those pics have been seen, I think. The triangular web "mounts" on the "lid" of the cabin structure indicate a horizontal moment at impact. The direction of failure (roll) of the mounts would indicate a horizontal vector the direction of which could be determined by the structure's installed orientation.

The control surface at the bottom (of the third photo) is the one that engendered the "aileron" vs. "elevator" discussion, I believe. I still think it to be part of the HS, perhaps the "trimmable" Horizontal Stabilizer as mentioned in the Prelim. What ever the case, make note of its conditon; it resembles the damage evidenced in the spoiler. If the vertical accel. was low enough to permit the relatively whole appearance of the Galley structure and was the result of a horizontally expressed aspect, I would emphasize the poor appearance of the HS "part" (or aileron). A low speed pancake would suggest larger more intact pieces of the airframe. I think what the control surface damage suggests is high speed flutter.

Finding parts from "all locations of the a/c" (my paraphrase) reasonably co-located but showing variable damage would argue against "intact at impact." A very robust external piece is virtually destroyed, but an internal structure is reasonably intact indicates to me a prior disintegration of some kind. Finding parts in a small area (if that is the case) merely means the ballistics of all parts of the a/c were aligned vertically after a possible breakup and descent to the Sea's surface.

Will

captainflame I think I understand what you may mean by that.

Mr Optimistic

8th Jul 2009, 16:57

thanks. Considering the damage evident in an auto crash at 60 mph I find the 'lack' of damage (crushing and buckling of panels, intact joints, lack of 'swipes' by adjacent structures) intriguing.

ClippedCub

8th Jul 2009, 17:05

You are confusing side-effects with the essential requirements of spin entry and spins. And since like Dani, you wish to protect and retain your pre-existing mis-understandings I won't require you to change. Since this thread is about AF447 it would be inappropriate to sidetrack and give you flight instruction. I'll let my statement on spin entry stand, it is entirely accurate. Ignore if you wish. Hope that helped.

So you're saying spin entry is stall and roll-off. Not my understanding nor experience. Thought you were supporting the concept of stall and sideslip producing a spin. You can have stall and roll off without a spin. The roll off stops when the lift is dumped naturally. If you have stall and sideslip you get a spin if not corrected. Understand it appears the roll off is producing the spin to most. NASA has some elementary diagrams explaining the force balance during spins. We're on different levels. Good luck.

Will Fraser

8th Jul 2009, 17:29

Along the lines of my previous post above, I would include other parts and note the relatively large discrepancy in energy absorption performance. Again the Galley, being large and relatively light, suggests it was uprooted rather "gently". Now look at pieces of the cabin liner that include penetrations (manufactured) for ports. Small, torn violently (I would say) into small irregular shapes. I doubt this liner is CFRP, it is expensive, and high impact plastic would perform as well in any conceivable line duty. This material is very strong in shear, though thin and light. Any forces that produced a large enough force to tear it into small pieces would be expected to shatter the Galley into small bits as well. The force at work for liner failure, including the highly energetic destruction and delamination of the Crew's Rest capsule, would seem to be a separate event from entry into the water at a velocity low enough to allow for a gentle uprooting of the Galley. (Noting that this would be in disagreement with the Preliminary Report).

captainflame :ok:

Hyperveloce

8th Jul 2009, 18:08

The Eurocockpit website (Eurocockpit - Accueil (http://www.eurocockpit.com/)) published today some interesting facts about the "unreliable airspeed" procedures, when the flight safety is impacted, as they are applied by the operators (at the date of the accident) and as they appear in the latest version of the Airbus QRH (at the date of the accident): the instruction to take in account the stall alarms in the operator procedure is no longuer visible in the Airbus QRH.
Jeff
PS) the differences between the two procedures can be seen page 67 of the english version of the BEA report.

PJ2

8th Jul 2009, 18:45

If I may...

A key understanding in philosophy and to a lesser extent, linguistics is, speakers of different languages "see" the world differently - direct translation is therefore not possible - "equivalency" is not possible.

Who would have thought that what many would have considered a straightforward phrase such as "ligne de vol", (which I took literally as "line of flight" which meant a more or less flat attitude because that is the way the airplane "is" when in flight, but descending in a vertical trajectory, "stalled but with little yaw") could be interpreted in so many ways. It teaches us that language is a huge part of our "reality" and not just a tool for communication. (if that's what it is, it's doing a very poor job).

The disagreements on the BEA language, the interpretation of "spin" and "flat", the abiding reservation or assured bravery with which "facts" and causal chains are entered, all have less to with what happened than with language. In this sense, the original, French BEA is not the "defining" document but nor is any translation into any other language. It is one document written very much in the manner in which the discussion has unfolded here. We may be certain that the strong views and disagreements are solid, primary factors in this report and in any other accident report. Whether truth emerges is a matter of such dynamics, not a matter of what actually happened. We are profoundly human and cannot escape interpretation - we are always "inside" interpretation because there is no "fixed" referent outside us which language may "call upon" and upon which we would all agree.

We might say that this is trivially obvious - until we run across genuine, serious, deep disagreements on words whose only commonality is the spelling of them.

Back to lurking in the FCOM...

PJ2

p51guy

8th Jul 2009, 18:52

The vertical G loads means it hit flat or almost flat. The flat spin theory could explain it if that is what happened but isn't it more likely with multiple instrument and autopilot failures that they ended up in a spiral dive and may have been trying to recover wings almost level and hit the water flat at a high sink rate? If that is all the data they have, high vertical G loads, the flat spin is just a possibility among others.

NOTanAM

8th Jul 2009, 18:53

First, let me say that as my nick says well, I'm not an airman. But I enjoyed enough this loooong thread to propose you something official about the translation of "ligne de vol" from Transport Canada, and from an officially bilingual country. From their airworthiness manual in French:

Rglement de l'aviation canadien - Partie V, Manuel de navigabilit Chapitre 525, Sous-chapitre C (http://www.tc.gc.ca/AviationCivile/Servreg/Affaires/RAC/Partie5/Normes/525/sous-c.htm)

scroll down the page to section 525.479. Do you see something familiar in the section's title? (and the first words of the section for that matter)

Now get back to the top of the page and click on the "English" tab. Get back down to 525.479 and now, what do you see?

OK, too lazy for this exercice? So, "ligne de vol" = "level attitude" at least to the ones making the flight rules around here.

Hoping this settles that one for good and for all.

Jean

Lemurian

8th Jul 2009, 18:59

This argument is getting boring.
As you don't agree on vocabulary / semantics, take this example ( I am French, a pilot and teach flying,. that should do to my credentials, right ?)

Take a tail dragger just before it starts its takeoff roll ; it sits on its tailwheel.
Now, accelerate, the pilot will give a forward control column movement ; the tailwheel raises and the pilot stops the movement there : He's now accelerating and he has put his aircraft "en ligne de vol".
That, and only that aspect is "en ligne de vol".

Another aspect of this discussion that's getting silly is people beating to death the different and seemingly contradictory aspects of the debris to promote their own ideas (and bashing the BEA at the same time).
Considering that the airplane is some 60 meters long - or 200 feet -, is it really difficult to understand that the same forces were not seen throughout the whole structure : some parts hit first (whether the airplane was en ligne de vol or not), that initial impact forces might have been seriously diminished through the energy absorption of the first "hits", including the dissipated energy through structural failures or breakages and finally that it would be surprising that we won't see some whiplash effects.
To think that the aircraft hit the water verically in a flat attitude, meaning that the impact was a single one and concerned the whole structure at the same 1,000,000 th of a second is silly and denotes an astonishing misunderstanding of dynamics.

rgbrock1

8th Jul 2009, 19:18

I've noted with great interest the topic of languages and translations and the
consequence of losing "meaning" in translation.
My native language is American English. However, I am bi-lingual in that I can speak, read, write AND UNDERSTAND, in German as well as in American English. (I spent 12 years of my life living with the natives in Germany!)
Whilst learning German, slowly at first, I came to the realization that some thought processes must also be modified somewhat when speaking, and listening, in a non-native language. To impart an idea or thought sometimes requires the adjusting of the mental processes involved in speech and understanding the intent behind that speech. Sometimes that which is intended in speech is not "correctly" understood by the recipient without a reciprocal adjustment in thought process as to the intended meaning being conveyed.

So, yes PJ2, I fully understand your excellent synopsis above.

PJ2

8th Jul 2009, 19:32

rgbrock1;
I fully understand your excellent synopsis above.
Fascinating comment from one who experiences what I can only write about, thanks.

Under the heading of "and now for something completely different", the notions and ideas of Jacques Derrida, (Fr. philosopher, d. 2004) express profound observations, and posit fundamental differences with the way language is comprehended "ordinarily", (as does Martin Heidegger). 'nuff drift. Thanks again.

abricot

8th Jul 2009, 20:00

If I may...

I noticed that there is a debate on the BEA report and the vertical acceleration and flight attitude at impact.

Post #3331 has a good point about linguistic considerations.

As a French native speaking, I feel that the key sentence in the BEA report is quite odd, grammatically incorrect. In contrast the rest (whole) of the document is quite well written and clear.

"l’avion a vraisemblablement heurté la surface de l’eau en ligne de vol, une forte accélération verticale." would translate as "the plane likely hit the water surface 'en ligne de vol', a strong vertical acceleration". (sic)

Again as a native French speaking it sounds like the author was not confident in this specific phrase or didn't understand what (s)he was writing.

Maybe you should get back to the hard facts (splatten things photos) and disregard this particular odd sentence.

Excuse my french, hope this helps, just my two cents...

BOAC

8th Jul 2009, 20:17

abricot - 'sound' advice. I would also ask that the welter of posts about stalls/'flat' spins/whatever is tempered by the fact that neither we, nor, I believe, BEA, ACTUALLY know how it hit or what made it fall from the sky, so to get to minutiae at this stage is rather pointless. Trying to determine failure and impact events from jpegs on the web is also a rather daunting task.

I watch this thread for 'news' and have become jaded by the intensity of to-ing and fro-ing here about what I feel are inessentials.

Anyone got any NEWS - or perhaps some more 'good advice' for the younger pilot and design generation instead?

EDIT: Regarding Heidegger - his writings are 'notoriously difficult':)

takata

8th Jul 2009, 20:18

Hyperveloce:
about the "unreliable airspeed" procedures, when the flight safety is impacted, as they are applied by the operators (at the date of the accident) and as they appear in the latest version of the Airbus QRH (at the date of the accident): the instruction to take in account the stall alarms in the operator procedure is no longuer visible in the Airbus QRH.

Hi Jeff,
I wonder if you fully understood the sense of this paper. What is written is that the memory item from Air France QRH "IAS Douteuse" (in French) slightly differed from official Airbus QRH (in English) concerning the "respect the stall warning". Then Air France informed its A330/340 crews of a change after June 5th. Nothing changed in "Airbus QRH" and it is not what you wrote above.

S~
Olivier

Grayengineer

8th Jul 2009, 20:38

The ditching stall scenario is being discounted mainly because there were no lifejackets on the passengers. I would put forth the explanation that there was no time to do this and to do so would require taking off the seatbelt which would be the last thing wanted of the passengers in what seems to have been an extremely fast and turbulent descent.

PJ2

8th Jul 2009, 20:57

Grayengineer;
in what seems to have been an extremely fast and turbulent descent.
I think so. Descent rates in the order of a hundred knots, plus-or-minus, for a fully-stalled, 205T high-drag, nutating mass would not be unusual. There would be planform (flat plate) resistance to higher speeds. The turbulence and the ride down would be quite violent given the massive amounts of air being displaced and resulting forces at work over different areas of the entire structure.

FanAviation

8th Jul 2009, 20:59

Yes rgbrock1 and P2. As a Frenchman living and working in the UK for many years I can feel the differences everyday. There are more than words in a language, there is culture so no translation can match that. I too can notice my "thinking process" changes from one language to the other. We are very lucky people so we should be very nice to those who believe "their" language and culture are "the" language and culture...
abricot: Agree with you the sentence you quote is incorrect ("avec" is missing) and if you are French you know this has nothing to do with not being confident or not understanding what (s)he was writing it is just a mistake in the typing: a word was omitted and nobody noticed it. I didn't notice it either when I read the report the first time... and on page 72 it is correctly typed. "pas de quoi fouetter un chat..."

Will Frazer: I was trying to help by explaining what a frenchman can read between the lines. It was not my intention to validate the BEA report I have no qualification for that, however I am not dumb and I know what is at stake in the report... I have a lot a relatives and friends in the Airbus and Air France environments I suppose that is as good as your friend with a PhD in French...
My sole intention was to help, I will remain silent.

HarryMann

8th Jul 2009, 21:07

FWIW

In free fall in a stable flat attitude at 205t, terminal velocity could be in the region 200 ft/s ~ 300 ft/s - at sea level density. (obviously back of a fag packet calculation, but might give an idea)

Thats as little as 2 minutes from cruise altitide

Let's all try to keep up shall we... ;)

HarryMann

8th Jul 2009, 21:14

Also...

Do we even yet know if the Captain was definitely resting and if so, whether he even made it back to the flight deck..
If he was and the answer was no, could current and past A330 flight crew confirm he would likely have been called back if there was time to focus on such things.

If this could be shown we perhaps could say with more certainty that this a/c did indeed meet its sad demise after one rapid fall from cruise altitude

takata

8th Jul 2009, 21:16

Abricot:
As a French native speaking, I feel that the key sentence in the BEA report is quite odd, grammatically incorrect. In contrast the rest (whole) of the document is quite well written and clear.

"l’avion a vraisemblablement heurté la surface de l’eau en ligne de vol, une forte accélération verticale." would translate as "the plane likely hit the water surface 'en ligne de vol', a strong vertical acceleration". (sic)

Again as a native French speaking it sounds like the author was not confident in this specific phrase or didn't understand what (s)he was writing.

Maybe you should get back to the hard facts (splatten things photos) and disregard this particular odd sentence.

Hi,
Sorry but no. Be sure they do know exactly what they were talking about and this "little syntaxical blunder" (a comma instead of a coordination agent) may be explained if the text was edited at the last minute. Either they removed something in the description of the impact, either they added the last part of the sentence ("une forte accélération verticale).

S~
Olivier

Squawk_ident

8th Jul 2009, 21:21

NOTanAM
First, let me say that as my nick says well, I'm not an airman. But I enjoyed enough this loooong thread to propose you something official about the translation of "ligne de vol" from Transport Canada, and from an officially bilingual country. From their airworthiness manual in French:

Rglement de l'aviation canadien - Partie V, Manuel de navigabilit Chapitre 525, Sous-chapitre C

scroll down the page to section 525.479. Do you see something familiar in the section's title? (and the first words of the section for that matter)

Now get back to the top of the page and click on the "English" tab. Get back down to 525.479 and now, what do you see?

OK, too lazy for this exercice? So, "ligne de vol" = "level attitude" at least to the ones making the flight rules around here.

Hoping this settles that one for good and for all.

Jean

In Canada all officials documents are issued/published in both languages. Now that we hold what might be a valid official translation, I think that can be stopped all the brain storming to scan, analyse, interpretate and translate in the best way possible the terms "ligne de vol" don't you think? Or should we have to start an endlessly discussion on how to translate "level attitude" in French?
It doesn't mean that I endorse the fact that this aircraft hit the sea in a level attitude or not (I don't know) but if you agree to this translation, it might be accepted by all of use once and for all?

JD-EE

8th Jul 2009, 21:40

Hyperveloce, regarding SatCom the simplest pattern is a slightly pinched bubble. A dimple in the direction of aim is "way off base" as does a null at zenith. There are steerable null antennas that can do this. There's no utility for such technology with Inmarsat.

And for reference Inmarsat runs in the 5.5GHz to 8GHz region. I believe exact frequencies are on their website (or Wakipoodle.) Up there St Elmo's fire static would have some presence but not very much, I believe. My experience is that the EMI effects of static discharge go down somewhat with frequency above VHF. But I suppose it's a good option for the outage period if there might have been some discharge at that time on the probably track the plane took.

JD-EE

surplus1

8th Jul 2009, 21:44

The ability to take the Airbus into Alternate or Direct Law resides within the design of the autoflight system but is a profoundly non-standard approach with this design and is entirely within test-pilot territory.

I state this strongly because it is not even in the realm of an "ad-hoc, emergency response" to a badly degraded aircraft or flight control system. I could not see this kind of system intervention condoned or even considered by any Airbus pilot nor can I see it as a legitimate response in the present discussion.

Thank you PJ2, you have answered my question. As the only person in the thread that I know to have been an A330 Commander, I put great credence to your remarks. As I’ve already stated – I have never flown any ABI product or any other FBW transport. My very limited knowledge of FBW transports is all ‘book learning”, and far removed from thorough. I have no hands on experience nor do I have the advantage of an AOM to which I may refer..

I believe I understood the difference between the ABI concept and the Boeing concept prior to your post. I just wasn’t certain if there was some acceptable method for the crew [other than a switch] to bypass the other modes/Laws and go to Direct Law in a single step. I now understand there is not.

I understand that in the Boeing actual control of the servos is still achieved by wire as it is in the Airbus when in Direct Law/C* Law. I know that there are no cables, pulleys or push rods. Both airplanes are still controlled “by wire”. It is not a major issue for me, just a difference in philosophy.

I am not challenging that difference in philosophy here as I do not think it relevant to the accident. They were not in a Boeing and there is no point in debating any subtle differences that may exist nor the different thought processes of the respective manufacturers.

The essential decision by the design and engineering people is, because the autoflight system is beyond it's design capabilities either during a serious system failure (hydraulic, electrical or data-loss) or a "jet upset", (> 10deg ND, 30NU, 50deg roll, approximately), it can no longer reference and interpret the situation the aircraft is in and necessarily hands control over the flight crew.

That’s good information and part of what I was getting at, perhaps too indirectly by not trying to ruffle any feathers. My apologies if you felt your's were.

I knew that there had to be limits to the autoflight system, I just didn’t know what they were. Now that you’ve told me, it fits right into my theories regarding the possible cause of the event. I am not implying nor did I mean to imply that the upset was caused by the autoflight system. In fact I think that whatever happened to the airplane was the cause of all those messages sent after it occurred and during its duration. I believe that the upset would just as readily have occurred in a B777 as it did in the A330 given the identical scenario. Whether or not it affected the recovery attempts that must have followed is wholly unknown and I’m not speculating that it did or didn’t.

In and encounter with extreme turbulence the aircraft could easily, in my opinion, exceed 10deg ND, 30deg NU, or even 50deg of roll (although not so likely the latter) in either type. If that should happen you say it “hands control over to the flight crew”. I assume that means it reverts (or degrades as you put it) to the equivalent of Direct Law. Is that correct?

Any one of five flight control computers on the 330 will provide full use of all flight controls without restrictions.

Excellent and just as I surmised; there is a great deal of redundancy. Redundancy is required in all critical systems, including flight control computers. The more a particular failure mode is considered to be possible or likely, the greater the redundancy provided. Next question: What happens should all five computers become inoperative at once or in rapid succession? I think I know but I would like you to tell me.

I have to emphasize that there is nothing in the A330 design in terms of pilot interventions that were not available in the B707/DC8 design. The flight control computers do not mysteriously "modify" pilot input to do what the engineers and designers really want but haven't told the flight crew.

That is understood and in fact I took it for granted. It could hardly be otherwise or you would need astronaut training and have to revert to the phrase: “Houston, we have a problem”.

Whether or not what “they told the flight crews” has been adequate, or said crews got the ‘memo’ is another matter. Given the many recent “incidents” and the changing procedures, it appears it may not have been. When there is much complexity and information is inadequate the otherwise benign can readily become the mysterious. Like it or not, pitot failures will cause loss of data but should not create pitch-overs or other erratic behavior. The fact is they appear to have done just that.

To be clear because there is a question, in Alternate law 1 & 2, pitch law is referenced to 'g' loading, (same as Normal law). The AOM does not specify that Pitch Alternate Law restricts 'g' loading to "2.5" but I suspect they do. In Direct Law, the aircraft is a "DC8".

The essential question is, "can the pilot get whatever 'g' s/he can pull above certification limits (2.5 positive, 2.0 negative, flaps up)? The answer is, yes in Direct Law and likely no, in pitch alternate laws 1 & 2, (1 is the same as 2 in pitch).

I understand that as well. I do not mind your being “direct” at all, that is what I wanted; somebody who knows the airplane who will give me a direct answer and not a lot of malarkey. I trust you won’t mind my being direct either.

I don’t need to know the intricate programming of the software, I just need to know – what will it do - in a given set of circumstances – and what will it not do. You have been of great help. You answered my question and you also confirmed the beliefs I already had.

In other words, there are indeed limits to the capabilities of Normal Law, as well as Alternate law 1 & 2. Whether they are measured in terms of “g” or in terms of pitch up, pitch down, and roll, those limits CAN be exceeded, perhaps not by the pilot, but by other forces – such as extreme turbulence.

Although I may not have stated it with sufficient clarity, that’s been my premise all along and the reason for my queries. If I understand you correctly, that does NOT mean that the pilot is suddenly handed an unflyable airplane. It just means that he is now flying it in the equivalent of Direct Law. The fact that the signals to the actuators/servos are by wire, rather than by cables or rods is irrelevant.

In the event of a total electrical failure (not relevant to AF447 IMO) and/or loss of hydraulic pressure from the engine driven source, the pilot would still have ship’s battery to the ESS Bus (or whatever you call its equivalent) and hydraulics and electricity both from the RAT – if it deploys and functions. The airplane is controllable for at least battery life (I guess about 30 min) while the crew restores a better source of electrical power and/or relights and engine that supplies hydraulics. The airplane must have at least 3 hydraulic sources [A, B, & C or whatever nomenclature is used.], which is quite standard. Since it is a twin, either engine running would be sufficient as a source of both electrical and hydraulic power.

If total electric power is lost and cannot be restored or provided by the RAT, when the ships battery dies the ability to operate the servos ends and control would be lost. Likewise, If hydraulic pressure cannot be maintained by the RAT, or all fluid is lost, functional servos cannot direct non existent pressure to any control, and control is again lost.

My main point is: In extreme turbulence the limits of pitch, bank, roll, yaw, speed and “g” associated with Normal, Alternate 1 & Alternate 2 “LAWS” can, one or all, be exceeded in short order. I suspect that such exceedence, if experienced, would most probably trigger a host of warnings and flags in rapid succession – just as it triggers AP and A/THR disconnect.

If the airplane is heavy and already flying at or near is maximum altitude, an extreme updraft could easily place it above that maximum altitude and take it into the “corner”. In that case it will upset. Whether or not it could be recovered from the upset is pure conjecture. Such an updraft followed by a similarly severe downdraft could fail the horizontal tail surfaces or the fin, or the entire tailcone. In other words, extreme turbulence is the equivalent of “Tilt” in a pinball machine. Game over.

Feel free to correct me please, if you find any of this thinking to be off-the-wall. I’m not talking about a bump or two here or even about severe turbulence. I’m talking about extreme turbulence – which is essentially an unknown quantity – greater than severe. I’m not aware of any transport that has survived an encounter with extreme turbulence. Correct that too if you have knowledge of such and instance.

Did it happen like that? I do not know. I just know that AF447 was lost. We owe it to our brothers who flew it and those who rode on it to leave no stone unturned until we know why – that it may not be repeated if humanly possible. This I believe necessary even if one or more of the overturned stones happens to reveal unpleasantries.

I hope this is of some help - I'm being a bit "direct" only to save space and not to dismiss concerns. This is the way the system works - there is only complexity, but not mystery.

I say again, I have no problem whatever with your being “direct” and hope that you have no problem with my being equally direct.

Agreed, I see complexity, perhaps more complexity than truly necessary, but I do not see mystery.

In very broad terms, I see FBW as necessary in military applications. The maneuverability of a modern fighter cannot be achieved unless it is inherently unstable and inherent instability cannot be controlled without the aid of computers.

In transport aircraft that is not the case; they are inherently stable. We have it and are expanding its use because it is supposed to provide greater efficiency, less weight and save money. Does the cost of all the bells and whistles actually justify the effeciences gained? I don’t really know but I suspect not.

Me thinks the ultimate goal of automation is the eventual elimination of piloted aircraft. Think of the money that would save and you’ve just justified the cost. We’re a very long way from that but eventually it will be achieved and passengers will be quite happy with it assured as they will be that absolutely nothing can go wrong, go wrong, go wrong.

Meanwhile I will hope that an A380 doesn’t vanish in the night on its way to Perth while its crew leafs through the QRH in search of some obscure procedure, or fall victim to a disgruntled Bedouin with 500 souls on board. I hope too that the Dreamliner’s resin doesn’t become unglued or succumb to an undetected invisible crack in its fail-safe fuselage, or that its multiple electric motors that replace the hydraulics will not mysteriously fail when needed. We live in interesting times.

What happened to AF447 after 0215Z is immaterial in terms of systems design, aircraft response and crew handling.

That’s a pretty strong statement to make given the data currently available. Is there something you know that the rest of us don’t, or is that just your version of conjecture?

I note that the shuttle accidents are referenced in comparison to automation accidents regarding "tons of money" etc.

You misread my intent. The reference to the Shuttle bears but one resemblance to AF447 and it is this: Humans are not infallible at any level and neither is the technology they develop. Technology is also not superior to the forces of nature. The technology did not fail in the Shuttle losses; humans failed. As Robert Burns would say:

"But, Mousie, thou art no thy lane,
In proving foresight may be vain;
The best-laid schemes o' mice an 'men
Gang aft agley,
An' lea'e us nought but grief an' pain,
For promis'd joy!"

einhverfr

8th Jul 2009, 21:46

ttse:

Depends entirely on the type of spin and rate of rotation. A deep-stall with slow rotation (i.e. flat-spin already discussed lots)could be a better all-around fit.

Well, there are a couple problems with that, still. Note, I am not discounting entirely the possibility of a spin. I am just saying it is not consistent with the findings of the report.

If you had a spin from altitude, I would expect the plane to hit at a near vertical vector with very little forward/backward acceleration. Also unless the rotation was very, very slow, the sideways inertial forces would still be a major (rather than minor) component to the tail failure. However the report found that the rudder failed forward with a slight left-ward twisting element (it is possible that this element could have been sufficient to throw it clear of the fuselage).

At 4 secs per rotation in a flat spin from altitude, I would expect sideways and forces to be a substantial fraction of the vertical forces and the forward deceleration to be negligible. Hence the VS would have failed sideways (perpendicular from the fuselage) with perhaps some other slight vector added representing what little was left of the original fight vector. Remember that the VS is close to the extremity of the spin, so the centrifugal forces are very high there.

On the other hand, in a low altitude stall, we would expect strong forward and vertical forces, along with some minor twisting as the airframe hits the water not quite level (due to wind). This seems most compatible with the findings to date. Not that the findings are infallible at this juncture.

The basic issue is that, absent air resistance, an unpowered fall from a specific vector will be largely parabolic (roughly comparable to a plane in flat spin, though a spinning aircraft, depending on wind, might generate sideways Magnus-effect lift, changing trajectory, but shouldn't be that substantial in a large airliner). However air resistance flattens this parabola, resulting on an even more vertical impact and less forward velocity. I would expect that if you dropped a rock out of a plane at FL350 and mach 0.8, it would impact the ground nearly (though not quite) vertically.

Hope this helps.

Hyperveloce

8th Jul 2009, 21:51

Hi Jeff,
I wonder if you fully understood the sense of this paper. What is written is that the memory item from Air France QRH "IAS Douteuse" (in French) slightly differed from official Airbus QRH (in English) concerning the "respect the stall warning". Then Air France informed its A330/340 crews of a change after June 5th. Nothing changed in "Airbus QRH" and it is not what you wrote above.
S~
Olivier

Olivier,
Well, in the operator procedures you find the instruction to take in account stall alarms even in the case of unreliable airspeeds (AoA based), and not in the aircraft manufacturer's QRH. Strange to term it a "slight" difference since the two versions could induce two opposite behaviours for crews facing both stall alarms (and possible ECAM status messages of "risk of undue stall warnings"). Sounds also weird that there can be two "slightly" different versions of a same memory item at the same time ? the BEA report page 67 states that the two slightly different memory item were both the versions in force for the operator and for Airbus at the date of the accident. The note of Air France of the 5th of June does not seem to be to inform crews of a change after June the 5th, it is a reminder of the procedures already in force (*). Is it a correct understanding ?
Jeff
(*) "Sans attendre les premieres recommandations du BEA et/ou du
constructeur et sans prejuger de leur contribution a la sequence des
evenements, il nous parait important de rappeler a tous les pilotes Airbus
que..."

HazelNuts39

8th Jul 2009, 22:06

Re: #3353 (Squawk ident)

Quote:
Or should we have to start to endlessly discussion on how to translate "level attitude" in French?
/Unquote

That would be pointless, because the french version IS probably a translation from the english version which, as far as I can see, is (almost) a carbon copy of the US airworthiness regulation FAR Part 25.

Regards,
HN39

ttcse

8th Jul 2009, 22:14

einhrvr,

After the calcs guys did earlier on the tail's horizontal velocity based on a 4sec/rotation ballpark, I too would wonder about having/not having evidence of sideways movement on the fin at impact. That's why I've been backing away from a standard spin or a flat-spin with high rotation rate.

One thing the 'failed slightly forward' represents to me was either slightly nose-down and/or with a slight forward horizontal travel at impact.
These seem to conflict with a flat-spin for an A330s as far as I know(I HAVE seen A330s fly over in the middle of the night going between Cancun and Vancouver BC:ouch:).

Edit: One thing the 'slightly twisted to the left' represents to me was some form of rotation, I'll admit a spin isn't the only way for that to happen.

If it were a low-altitude stall, it would really need to kill forward travel. Can be done. Not my favorite scenario.

ttcse

8th Jul 2009, 22:34

JD, not unless the flight continued from 02:10 and beyond 02:14 for some more minutes. The zone of east drift challenges and has the potential to replace the backwards drift projections.

Edit:If east drift replaced backwards drift projections, it might make more (or perfect) sense if af447 came down further west. Then the currents initially took debris eastward and then shifted to north-northeastward.

Otherwise, you would need to address and pull in all the posibilities for explaining why acars stopped at 02:14 but the plane continued on for some time.

surplus1

8th Jul 2009, 22:45

Einhverfir,

Well, there are a couple problems with that, still. Note, I am not discounting entirely the possibility of a spin. I am just saying it is not consistent with the findings of the report.

Agreed. It seems also that your arguments against a flat spin [not a normal spin] are based entirely on the credence you give to the report. You have accepted mentally that the fin separated from the rest of the structure in the manner that they surmised -forward on impact. Even they only surmised - you are taking it as fact.

Where would the Board get the time to make a thorough scientific analysis of the recovered VS and where would they physically do that? On an island off the coast of Brasil? On the deck of a ship? Did they fly it back to France before the report?

If you had a spin from altitude, I would expect the plane to hit at a near vertical vector with very little forward/backward acceleration. Also unless the rotation was very, very slow, the sideways inertial forces would still be a major (rather than minor) component to the tail failure. However the report found that the rudder failed forward with a slight left-ward twisting element (it is possible that this element could have been sufficient to throw it clear of the fuselage).

At 4 secs per rotation in a flat spin from altitude, I would expect sideways and forces to be a substantial fraction of the vertical forces and the forward deceleration to be negligible. Hence the VS would have failed sideways (perpendicular from the fuselage) with perhaps some other slight vector added representing what little was left of the original fight vector. Remember that the VS is close to the extremity of the spin, so the centrifugal forces are very high there.

All of that is quite logical but again, you are basing it on the VS being attached to the rest of the airplane during the flat spin. Is there some reason why you have decided that it could not have separated before that flat spin began and thus caused the flat spin? Is it impossible that the forces on it after the upset could have caused its rearmost attach point to fail first? What if the horizontal stabilizer failed downwards and tore loose from it then causing it to come off? There are so many possibilities.

On the other hand I am suggesting that there would not be a flat spin if the VS remained attached. What would cause the flat spin would be the failure of the entire tail cone [aft of the pressure bulkhead], or of the VS alone. In turn, either one of those would likely cause the engines to leave their mounts. What was then remaining would be the fuselage and the wings. They would then fall near vertically, somewhat like a leaf, with very little rotation, until impact.

On the other hand, in a low altitude stall, we would expect strong forward and vertical forces, along with some minor twisting as the airframe hits the water not quite level (due to wind). This seems most compatible with the findings to date. Not that the findings are infallible at this juncture.

How do you get the airplane from where it was in cruise, high altitude, to the point at which this low altitude stall occurs? Does it just glide or fly on down smoothly? If so, why; and wouldn't that take about 90 miles? Are the engines running in your scenario or are they flamed out? What exactly do you mean by low altitude - how low?.

If it did not stall all the way down from FL350, why would it suddenly stall at low altitude? If it made a last minute pull up into an accelerated stall - how did the pilots manage to see the ocean and judge when the should pull up? Was it diving at very high speed before this happened?

There are just too many IF's for me.

PEI_3721

8th Jul 2009, 23:45

surplus1, {post 3358} you appear to have misunderstood the difference between the flight control system (FBW) and the autoflight system. The airbus follows a similar concept as conventional aircraft, except as stated that the technology used in flight control system is FBW.
See A330 Flight Controls. (http://www.smartcockpit.com/plane/airbus/A330/)

With the autopilot engaged, if the aircraft’s reaction to a gust in turbulence is beyond certain boundaries (pitch +25, -13, roll 45, speed, AOA, well before the constraining ‘g’ limits of the FBW system), the autopilot disengages (with alerts) and hands a fully functioning aircraft (controls) to the crew, there is no change in control law. Your assumption of a change of law is incorrect.
In manual flight the control system limits the manoeuvre within the constraining boundaries.
See A330 Auto Flight. (http://www.smartcockpit.com/plane/airbus/A330/)

Changes in flight control law are generally the result of computational system failure and/or input failure, this includes electrical failures.
In this accident the comparator functions of the ADC inputs appear to trigger the conditions which would cause a change in control law.
See A330 Flight Laws. (http://www.smartcockpit.com/plane/airbus/A330/)

The limits of the normal law (protections) are no more likely to be exceeded when flying in any other law, than they might be exceeded in any conventional aircraft, excepting gross differences in the underlying aerodynamic designs. ‘IF’ turbulence caused an upset then it could have happen to any aircraft, and even exceeding the stated limits, it does not imply that control will be lost.

Your subsequent speculation about airframe failure is just too extreme, both from the scarce evidence available, and extensive research and previous turbulence encounters, which form the basis of certification standards.
This does not mean that ‘it’ cannot happen; just that it is most unlikely. In order to strengthen your speculation, then the reported weather would have to be correlated with other aircraft upset and failure events, and the assumptions within the certification requirements.
Although the reported storm cells appear to have been very large, they were not as large as some that have been recorded. There is no evidence that the aircraft entered a Cb.

Re post 3368, you might find your tenuous argument easier if you described the aircraft motion after a structural failure as ‘spin like’; who knows what the actual flight path modes would be without a fin or other large pieces of structure. Please do not cite the A300 accident; there are not enough similarities to be valid.

JuggleDan

8th Jul 2009, 23:48

I'd like to go back a few days ago, to a previous exchange (http://www.pprune.org/5039155-post2868.html) between singpilot and PJ2:
Sorry, I think Occams' Razor applies here. Yep, and it doesn't paint a pretty picture, frankly.
So there's everything to learn, and nothing to learn...depends upon who's doing the learning. There is the pitot issue and the response, and the broader issues of cascading failures possibly overwhelming crews.I probably have too much imagination, because when I red this, I felt like I was just a kid, watching two grown-ups discussing serious matters in a hushed voice...So I wondered what they were talking about, and I came up with a theory.
Maybe the computers have become so good at flying the planes that manual flight is now discouraged by SOPs and that training time is now reduced...
Maybe pilots nowadays don't accumulate as much manual flight time and hands-on practice as they used to...
And maybe sometimes it might make a difference between life and death...

The way I see it, if there is a lesson to draw from AF447, it could be that computers will never replace pilots, and that software test procedures will never replace manual flight training hours...
Anyway, since all this is derived from a couple of posts exchanged between grown-ups, it's likely that I just have too much imagination...

PEI_3721

8th Jul 2009, 23:53

JuggleDan, see http://www.pprune.org/safety-crm-qa-emergency-response-planning/379780-computers-cockpit-safety-aviation.html#post5041334 and other posts in the thread.

einhverfr

8th Jul 2009, 23:55

Surplus1:

Sorry if I wasn't clear on this case.

My view right now is that I lean somewhat against spin hypotheses and somewhat towards the idea that the VS separated during impact (there are a number of reasons it might not have impacted the fuselage in this case). I reserve the right to change my mind as more information comes in. In general I assume that BEA has somewhat more info than we have from just the photos. I assume the visual inspections in the reports are better than the photos we have been seeing. It seems that in the case of the VS, they had to modify the examination based on photos, so this area is more weak than I would like.

One issue here also is that the argument that the plane hit in a flat spin is, in my estimation, based in some cases on the BEA report too. So I figure if we can clear up points about what is consistent with the report, we can move on to further questions, such as whether the report is accurate.

Some elements of the BEA report are very important in this regard and some of these are important and well put together. For example the discussion of uniform compression damage across various sections of the plane struck me as quite odd. Other elements are far less certain at this point.

If we give the report credence, as to the direction of failure on the VS, then I think we would also have to assert that it separated on impact, because it would seem highly unlikely that the VS failed forward unless this was the result of inertial forces (again inertial forces would have been down + forward in a low altitude stall, and down + sideways in a flat spin).

Certainly some theories can be solidly dismissed at this time. For example, the idea that the plane was in a flat spin at 0210Z as this would not be consistent with impact even 4 minutes later.

Other theories, like entering a flat spin at 0214Z are harder to dismiss. At this point, they seem inconsistent with the BEA report (while a stall at low altitude with significant forward momentum is not). But as you say, the BEA report could be wrong about key things like the tail.

JuggleDan

9th Jul 2009, 00:00

The reason why the autopsy results are still missing may be explained by the French newspaper Le Monde (http://www.lemonde.fr/web/depeches/0,14-0,39-39805723@7-37,0.html) (To Be Confirmed, obviously):
Selon un haut magistrat français qui n'a pas souhaité être identifié, les autorités brésiliennes refusent de transmettre leurs conclusions portant sur 51 corps retrouvés dans l'océan Atlantique car elles n'ont pas encore ouvert d'enquête judiciaire mais seulement une procédure administrative.In other words (thx Google Translate): Brazilian authorities refuse to forward to the French the autopsy results because they have opened no penal inquiry yet, the ongoing procedure only being an administrative/civil inquiry.

Obviously, this news is dedicated to Will Fraser :)

ARFOR

9th Jul 2009, 00:11

PJ2 Thank you once again. Under normal (design) circumstances, all AC and DC busses remain powered; there is some load shedding, (galleys) in loss of generation.

As you say, the ECAM would display the failures and the required actions. FLR/WRN category messages would be generated and recorded by the FIDS, (Fault Isolation and Detection System), collated by the CMS (Central Maintenance System) and sent to the ACARS for maintenance action. In short, they would be a part of any transmitted messages. I take from that, it is almost impossible that a power plant failure occurred at or before 02h14z, therefore AC1 and ACARS were most likely operating and able to report any anomalies in engine operation (whilst the ACARS aerial was pointed skyward at least). What of ACARS (and AC1) after 02h14 if the 'controlled flight' theory were at all possible?

Which brings me neatly to another issue (amongst the many possible variables). The NW FO comment as provided by Greybeard Here's what the FO wrote in an email the day after:

... Entering the cloud tops we experienced just light to moderate turbulence. (The winds were around 30kts at altitude.) After about 15 sec. we encountered moderate rain. We thought it odd to have rain streaming up the windshield at this altitude and the sound of the plane getting pelted like an aluminum garage door. It got very warm and humid in the cockpit all of a sudden. Five seconds later the Captains, First Officers, and standby airspeed indicators rolled back to 60kts. The auto pilot and auto throttles disengaged. The Master Warning and Master Caution flashed, and the sounds of chirps and clicks letting us know these things were happening. MY bolding

Assuming no 'recollection' error (event sequence and/or timing), the AP and AT disengaged AFTER the speed indications had rolled back to 60kts, which based on exhaustive information provided here (including the ADR thinking time before DISAGREE), means the cascade of faults (in the AF447 case) might suggest the last recorded rudder travel limit prior to ALTN would have been a very low speed index (high travel available)? I followed that discussion very carefully, and it is still not clear in my mind if the above were possible/probable!? Which brings me back to your comment In cruise, an engine failure would require an immediate but small application of rudder, (gently!). As with all high-altitude flight one must be careful with the use of controls because thin air provides so little damping effect. Providing rudder is used judiciously, roll-due-to-yaw is not a problem. You see my line of query i.e. due speed related upset prior to 02h14, or assem thrust related rudder application after 0214z following upset!

Along the same lines:-

surplus1 All of that is quite logical but again, you are basing it on the VS being attached to the rest of the airplane during the flat spin. Is there some reason why you have decided that it could not have separated before that flat spin began and thus caused the flat spin? Is it impossible that the forces on it after the upset could have caused its rearmost attach point to fail first? What if the horizontal stabilizer failed downwards and tore loose from it then causing it to come off? There are so many possibilities.On the other hand I am suggesting that there would not be a flat spin if the VS remained attached. What would cause the flat spin would be the failure of the entire tail cone [aft of the pressure bulkhead], or of the VS alone. In turn, either one of those would likely cause the engines to leave their mounts. What was then remaining would be the fuselage and the wings. They would then fall near vertically, somewhat like a leaf, with very little rotation, until impact.

xcitation

9th Jul 2009, 00:23

xcitation, WHEN would the passengers or crew have put on life jackets?

Not sure you are asking the right person the right question. Please re-read my posts. My apologies if it was that badly written that a lawyer couldn't discern my meaning.
If I interpret your question to be when would the AF447 cabin crew have instructed the PAX to don jackets. I think the SOP for this equipment would be for instructions to happen after ditching in the sea.

If the plane was in extreme turbulence please describe the sequence of events needed to don life vests and then tell me if that is feasible in a violently buffeting airplane. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif

JD-EE

Was that a rhetorical question (equally :confused:)
If not then for the first part I defer to cabin crew qualified on similar equipment; for the second part I would say it would be feesible but very unlikely especially if you are working with the flat spin hypothesis.

ttcse

9th Jul 2009, 00:31

einhrvfrOther theories, like entering a flat spin at 0214Z are harder to dismiss. At this point, they seem inconsistent with the BEA report Better still, upset and perhaps flat spin entry at 02:13:2x when the acars was lost for about 15-20 secs, as pointed out in the report.

Tree

9th Jul 2009, 00:41

The ability to take the Airbus into Alternate or Direct Law resides within the design of the autoflight system but is a profoundly non-standard approach with this design and is entirely within test-pilot territory.

Considering the scenario a Qantas crew recently found themselves in, I suspect there are some new Murphy's Law test-pilot members who have filed away the method in their mental toolbox. I filed it from day one on the Airbus but fortunately never had to use it.

mm43

9th Jul 2009, 02:05

PEI_3721;

With the autopilot engaged, if the aircraft’s reaction to a gust in turbulence is beyond certain boundaries (pitch +25, -13, roll 45, speed, AOA, well before the constraining ‘g’ limits of the FBW system), the autopilot disengages (with alerts) and hands a fully functioning aircraft (controls) to the crew, there is no change in control law.Thank you for that concise description.

It is worthy of note that the GS between 0200z and 0210z AOC positions decreased from 464KT to 463KT, possibly indicating that the chop conditions remained similar. However, GS may have significantly decreased just prior to 0210z as the a/c penetrated the Cb up-draught. A significant pitch up and latent heat transfer through condensation forming ice could probably be directly responsible for the AP "giving up". This in just a few seconds. G forces and sudden hell breaking out in this manner, is not the best way to start a recovery, especially as the pilots minds were probably engaged on why they couldn't log on to DAKAR using ADS-CPDLC, a procedural requirement 20 minutes before TASIL. Never mind not noticing the bad stuff on the WX radar.

mm43

JD-EE

9th Jul 2009, 02:12

xcitation, I probably should have said "could" instead of "would", my bad. You had stated that SOP was not to put them on. I was amplifying your answer with the question when could the passengers have put them on given the suspected extreme turbulence would severely bounce any passengers who unbuckled seat belts to start putting one on.

You stated it was SOP not to. I intended to append that it very probably was not physically possible. My wording got sloppy. Please excuse me.

JD-EE :O

Gringobr

9th Jul 2009, 02:21

I can imgine the BEA committee sitting arguing in the same way we are , with nobody agreeing on anything, except that here we probably have more qualified people

PJ2

9th Jul 2009, 03:00

JuggleDan;
Your comments sat pretty maturely for me - I think you get it. Not everyone does, usually because they fly a desk or a laptop. Many writers and safety experts don't fly but they sure get it as evidenced in their excellent contributions to flight safety. People who think that SMS is the answer to keeping accident rates down don't get it. 'nuff said.
it's likely that I just have too much imagination...
For a beancounting manager, yes. For a pilot, no. For present times, also a very mild, 'yes' but like I said, it depends upon who's doing the learning.

This is an extremely complex accident with a depth of possible analysis far greater than any recent ones I can recall - there are a huge number of issues "at rest", latent, in this accident and only a few of them are technical.

JuggleDan

9th Jul 2009, 06:51

PJ2,

Thank you very much for your kind answer. Quite frankly, a lot of my thinking was actually derived from your post #2628 (http://www.pprune.org/5034553-post2628.html). While I fully understand your position, your post gave me a feeling that having the SOPs discourage hand-flight looks like a pretty dangerous double-edge sword...

Back to the point,
For a beancounting manager, yes. For a pilot, no. For present times, also a very mild, 'yes' but like I said, it depends upon who's doing the learning.Actually, even the bean counters may actually learn a few good things: due to the crashes in June, insurers are likely to lose a lot of money. See for example Les assureurs aériens accusent leurs plus grosses pertes depuis 2001 - Transport - E24.fr (http://www.e24.fr/entreprises/transport/article108763.ece/Les-assureurs-aeriens-accusent-leurs-plus-grosses-pertes-depuis-2001.html) ("Airflight insurers acknowledge their biggest losses since 9/11").
Thus, they may put the airflight companies under pressure for more safety and risk reduction. I admit this is partly wishful thinking, but who knows...

BTW, I was positively surprised by some passages in yesterday's interview of AF's CEO (http://www.lefigaro.fr/actualite-france/2009/07/08/01016-20090708ARTFIG00504-af-447-tous-les-scenarios-du-drame-vont-etre-analyses-.php):

Il n'y a pas de contradiction entre la sécurité et l'économie. Quand on améliore la sécurité, on améliore l'image de la compagnie et on améliore logiquement ses performances économiques.
[SNIP]
Nous allons regarder à nouveau le contenu de la formation des équipages, la qualité des informations météo disponibles et la mise à jour des informations par des échanges avec le sol. A l'occasion d'un incident et à fortiori d'un accident, le retour d'expérience fait apparaître des possibilités de défaillance. Qu'elles aient ou non un lien avec la cause de l'événement, notre devoir est de les corriger.
In other words (thx Google):

There is no conflict between safety and economic performance. When safety improves, it improves the company public image, and thus mechanically improves its economic performance.
[SNIP]
We are going to review the contents of crew training, the quality of the available weather information and the ways information is updated through radio contacts with ground. Whenever an incident occurs, and all the more when it's an accident, analysis shows latent failure pathways. Whether or not they are connected with the cause of the event, it is our duty to correct them.

I daresay there is hope yet!

LeandroSecundo

9th Jul 2009, 07:27

Hi,

We are going to review (again) the contents of crew training, the quality of the available weather information and the ways information is updated through radio contacts with ground.This must had been a basis day work .. to perform those duties.
Seem's Air France was sleeping on their laurels and this last crash awaked them..
Yet many alarm bells were heard for years in AF (from unions .. from pilots)

They were dreaming and sleeping well .. and now they have short nights and make nightmares .....
Some AF heads are accountable for the bad outcome of this airline.

Bye.

LeandroSecundo

9th Jul 2009, 07:39

Hi,

BEA to bring Airbus down? BEA is not there for put Airbus or AF down or support AF or Airbus.
BEA is there for make a IMPARTIAL investigation with all their knowledge and publish the results and the eventual corrections or practices to be amended.
I hope this will be this way !

Bye.

ArthurBorges

9th Jul 2009, 07:41

I saw this item from Reuters just now at Air France dément tout manque de réactivité lors du vol AF 447 - Yahoo! Actualités (http://fr.news.yahoo.com/4/20090708/tts-avion-air-france-ca02f96.html)

It sources from Le Figaro, a leading national daily of conservative bent.

Anything between quotes is out of Mr. Gourgeon's mouth; the rest is journalese.

I have omitted some content.

In an interview published on Thursday in Figaro, Air-France/KLM CEO Pierre-Henri Gourgeon said pitot tube icing "may have been a factor" in the AF447 crash but "does not suffice to explain the accident."
He denied having access "to a secret recording from the pilot," one of the many rumors in circulation around this case.
He said "no radio recording was picked up between AF447 and (other) aircraft in the area."
"The Air France control center only became aware very gradually that something was going wrong."
Over six hours passed between last contact with AF447 and a first report to the BEA.
"We often lose aircraft over Russia, Africa or oceans and we find them. Because sometimes aircraft have radio malfunctions."
"Between 0630 and 0830 (LT France) it's still too early for Brest or Madrid to pick up the flight. It was only after connecting the dots between the numerous electronic maintenance messages and long radio silence that disappearance of the aircraft was suspected, at about 0830."
"Asst. Gen. Manager for Operations Gilbert Rovetto phoned me and said that ATC centres were confirming no contact with AF447 the one after the other. That meant we had probably lost an aircraft."
He said nothing indicated the seriousness of the situation to the technician on duty that morning who processed the 24 automatic messages from the aircraft.
He said the problems faced by AF447 were not the result of any negligence.
"There is no contradiction between safety and bottomlines (économie). When you improve safety, you improve the company image and you logically improve its competitive (économiques) performance."
The BEA report...affirms that the aircraft hit the water intact, practically in normal flight attitude, i.e. in horizontal position.

Dani

9th Jul 2009, 08:23

Surplus1:

If it did not stall all the way down from FL350, why would it suddenly stall at low altitude? If it made a last minute pull up into an accelerated stall - how did the pilots manage to see the ocean and judge when the should pull up? Was it diving at very high speed before this happened?

For me, the most likely scenario is still the same, after all that discussion: They stalled all the time. After loosing pitots and/or computers/screens and situational awareness, they flew around in the dark without knowing their speed and their attitude. They had overspeed and stalls, they where in a spiral dive.

Until they where below the freezing level, that's where the pitots reopened and let some true information get through.

Unfortunately, that was too low to recover.

Reminder: This is only my theory and is solely based on the same information you all have. And again: It's not important how they crashed but why. The impact theory is an interesting one, but not of great importance. It's clear that they crashed, and it's very likely because of the pitot icing. That's what we should discuss here.

WhyIsThereAir

9th Jul 2009, 09:29

It's clear that they crashed, and it's very likely because of the pitot icing. That's what we should discuss here.

These are causes, and then there are causes. Pitot icing was probably a cause. But there have to be at least two other causes:

What caused them to fly into icing and probable turbulance?
What caused them to lose control?The pitot icing problem can doubtless be comprehended and thus physically improved, even if it is impossible to solve in all possible cases. Improved procedures and training can likely also mitigate the situation. But if things stop with "fixing the pitot icing problem" then great opportunities for improved safety and pilot operational ability will have been lost. There are clearly opportunities here to at least:

Improve weather awareness for airmen (sat feeds, etc)
Improve cockpit->ATC/base communications in remote areas; or at least this one specific remote area
Improve the capabilities and training for DAKAR ATC
Provide an acceleration to R/D for improved WX radar and WX tools in general in the cockpit
Study the MMI (Man/Machine Interface) during critical situations such as occurred between 0210 and 0213 in AF447 and see if there are things that can be improved
Improve simulator training for unusual but possible situationsAll of that could come out of this accident. But if we simply decide to say "the pitots done the deed" and end there, many other improvements might be lost.

PJ2

9th Jul 2009, 09:49

JuggleDan;
Actually, even the bean counters may actually learn a few good things
. . .

I daresay there is hope yet!
I doubt it. Fought too many fights, seen enough studied ignoring of "inconvenient" data to believe any of that.

That's not to say they're not good - they are, and I know of dozens and dozens of ways that flight safety is protected, enhanced and otherwise "looked after". Otherwise the stats would be horrendous.

I don't focus on "beancounter parsimony". I focus on the propensity of very good, motivated people with earnest intentions and very high standards to normalize "normalizing the deviance". Airlines have extremely good safety records including the one I retired from - there are exceptionally good procedures in place to secure safe flight. That is not where the issues lie. The issues lie in being "satisficed" - proceeding with an air of satisfaction to the point where there may be a latent unwillingness to examine uncomfortable and even plainly inconvenient operational data. Seen it - been scared at the lack of curiosity or interest. Organizational issues are curious this way, and I will bet that Will Fraser was turning his attention to this much broader matter in the later posts given some of his comments on the "mileu" in which reports are written.

The story of an accident is not one of bad people doing poor work, or ordinary people succumbing to what Diane Vaughan termed, "amoral calculation" as in "what can we get away with?" That rarely happens in aviation, certainly not without result.

It is the story of earnest people trying to satisfy dozens of competing interests and priorities which, almost 100% of the time, are sorted benignly. The seeds of accidents are sown months, but more often years, before the occurence, in attitudes, in actions not taken and data not hearkened to.

These are not mysterious forces or anomalous contingencies. They are standard fare for any safety specialist, who will always wear a different pair of glasses than the operations managers and beancounters. The key is in the balance and that balance is set by a very active and robust two-way communication between those that must make money and those that ensure a safe operation. Over the decades I have become convinced that that conversation does not always take place.

PJ2

Lemurian

9th Jul 2009, 10:44

I daresay there is hope yet!
It never cease to amaze me how some "editing" can change the whole meaning of a newspaper article.
Actually, safety was a lot more on the minds of Air France people, including the pilot union SNPL / ALPA now , than a lot of posters think.
all...except our friends from Alter / Eurocockpit / rdio cockpit (they are the same people).
Back to the Figaro article,

Talking about safety, there is this passage, question and answer :

Qu'avez-vous vraiment changé depuis le très critique rapport Colin sur la sécurité aérienne ?

Je suis fier du rapport Colin, diffusé à tous les navigants de la compagnie, et qui montre que chez nous, il n'y a pas de tabous en matière de sécurité. En octobre 2005, nous avions confié à trois commandants de bord instructeurs d'Air France une mission d'analyse portant sur l'organisation et le fonctionnement de nos opérations aériennes. Depuis, il faut savoir que les recommandations de ce rapport ont été mises en œuvre dans tous les domaines : règles opérationnelles, organisation et sécurité des vols, formation des personnels navigants, exploitation et maintenance au sol.

I leave you to google translate that.
As an active witness / participant of the whole process, I find it quite insulting to find people with absolutely no idea on what an aircraft is made of, let alone how it operates, to emit judgments of value backed by nothing but a despicable agenda.
All the recorders of the airline - and I insist on the ALL - are systematically speed-read in order to detect (through a thorough and specific thresholding algorythm) mishaps, irregularities, deviations from SOPs, trends...etc... and the results are published in the bi-monthly air safety brochure, which every crew member receives. An Internet portal exists, parallel to the anonymous reporting system that exists in every serious airline.
In case one of this recordings shows a dangerous operation, the crew is called to explain the deviation and can ask for the legal help of the Union...The procedure can go a lot further, though rarely.
.....sorry, can't go further...
JuggleDan, the rant is not addressed to you.

Captain104

9th Jul 2009, 11:19

Danny, did you think about closing this thread?

Since days and weeks a group of about 6 to 8 experts, some retired many years spend an incredible amount of time posting in this thread page after page.
Could it be they are just entertaining themselves? And PPRuNe readers by spreading endless theories. They often start: I HAVE NEVER FLOWN AN AC/AIRBUS/FBW.......,BUT I THINK THAT.....
I doubt most of them have ever seen an AIRBUS cockpit inside or have the slightest idea about FBW, much less AB FBW laws. One item finished it starts all over again: french-english "en ligne de vol" translations, BEA conspiracy, flat spin, VS separation and so on and so on. In between the same questions asked and answered weeks ago several times.
IMHO pilots with adequate background concerning AC accident investigation are not amused. :(

ArthurBorges

9th Jul 2009, 11:27

Translation errors can be as deadly as pilot error.

I have learned a thing or two following this thread. It may be of some help to someone some day. We know not.

If I have injected bits of translation here, it was a perhaps clumsy attempt to thank you all for what I am learning here.

Please also note some non-native speakers of French or English in your industry may also find it useful and easy to remember because the vocabulary is presented in context instead of one term in a thousand on a laundry list of aeronautical terms.

Having been a moderator and forums administrator elsewhere, I can assure you there is nothing to stop the webmaster/owner(s) of this website from establishing closed/locked forums accessible only to the privileged.

Happy Skies, Sir!

Hyperveloce

9th Jul 2009, 11:31

Reading the BEA report/findings, and beyond linguistic barriers, I visualized the impact like this: http://img132.imageshack.us/img132/6169/impact.jpg
(nose up a bit exagerated, tail crushed on the surface absorbing part of the kinetic energy, snapping off the VS, airframe broke in two points, one allowing at the rear of the a/c a massive/brutal water inflow that may have stripped off the clothes, another structural failure in the aera of the Galley G2).
Some of you have produced alternative scenarii (in particular to account for the distorsions observed on the VS) which may be better visualizations
Jeff

Weeds round the prop

9th Jul 2009, 12:14

From a humble PPL:
If no further items are recovered, especially the CVR & FDR, then I suspect that the final report can be little different from the Prelim report. Thus, and this keeps me glued to the thread, one or more of the 'heavyweights' posting here will have posited a scenario close to 100% accurate. We are sharing the same data apart from physical observation of the small amount of wreckage, and the autopsy reports.

Regarding the endless thread concerning 'ligne de vol': I have not read anyone offering the possibility that the pressure hull and main spar, plus remaining attachments, just happened to hit water horizontal and bottom-down, ie. it could have tumbled and rolled from FL300+. The initial wreckage spread would still have been compact, viz Lockerbie.

Hyperveloce

9th Jul 2009, 12:31

"Fragments of the walls of the flight crew rest module were crumpled and those of the ceiling were deformed downwards. The floor was curved under the effect of a strong upward pressure from below. The connecting brackets between the floor and the walls were bent backwards" (page 38 of the BEA report, my emph.)
------
I am trying to understand this backward bending of the brackets (and to understand whether the floor moved backward relatively to the walls, or the contrary ?). Are there available schematics showing these connecting brackets anywhere ?
Jeff
PS) maybe this aspect can help to discriminate between the gliding hypothesis - with a relatively high incidence ? - and a turbulent fall with a nose up ?

lomapaseo

9th Jul 2009, 12:45

JuggleDan

Still, I wonder if the fault lies with AF only... What about the EASA, what about the SNPL?... Sorry, if I keep reusing the same metaphor, but some guys were supposed to be watchmen there. "Watchmen", meaning people who's job is to keep watch: where were they?...

I don't follow what you mean:confused:

What were they supposed to watch?

DozyWannabe

9th Jul 2009, 12:48

surplus1:
Me thinks the ultimate goal of automation is the eventual elimination of piloted aircraft. Think of the money that would save and you’ve just justified the cost. We’re a very long way from that but eventually it will be achieved and passengers will be quite happy with it assured as they will be that absolutely nothing can go wrong, go wrong, go wrong.
I can't 100% say for certain, but I'd say that is in all likelihood utterly inaccurate. The men who worked in aviation software that I studied under and my peers who went into that industry were absolutely adamant that it was not, and in our lifetimes at the very least would never be the case.

The only group of people speculating "the end of manned passenger flight" during the advent of the A320 were the self-same media who are regularly and rightly pilloried on here for not knowing their arse from their elbow when it comes to aviation. They were also the ones who promulgated the misunderstanding that "the computers can override the pilot", "the Habsheim A320 computer [sic] thought it was going to land" and other sundry inaccuracies that nevertheless sent a frisson of outrage through the piloting community that has never completely gone away. Admittedly AI didn't help themselves in the early days, but the foot-in-mouth statements were made by senior management and sales executives, *not* the engineering staff.

lomapaseo

9th Jul 2009, 12:50

Regarding the endless thread concerning 'ligne de vol': I have not read anyone offering the possibility that the pressure hull and main spar, plus remaining attachments, just happened to hit water horizontal and bottom-down, ie. it could have tumbled and rolled from FL300+. The initial wreckage spread would still have been compact, viz Lockerbie.

Yes, this was spoken of the first day of the release of the prelim report, but got lost in the endless spin discussion.

metaphor = a falling leaf. How does it hit the ground?

HHornet

9th Jul 2009, 13:06

There are still a lot of options re sequence of events from the plane being in the air to the plane in the sea. Is there enough information to work backwards?

Re: The galley unit that was recovered - at some point this section left the aircraft through a hole/break that presumably was the same size or larger than the galley section itself.

Can this wreckage or any other of the pieces narrow the possibilities as to the type of impact with the water?

TiiberiusKirk

9th Jul 2009, 13:18

I know that there has been quite a bit of discussion about the whereabouts of the Captain at the time of the incident. Yet it has always been assumed/agreed that there were no less than two alert crew in the cockpit as per regulations.

I was just reading a UK CHIRP report: http://www.chirp.co.uk/Downloads/ATFB/ATFB90.pdf (page 12), about a worrying incident.

The flight concerned had four pilots, two went to the bunks for sleep.

The cabin crew were then instructed NOT to contact the cockpit at all, as a third pilot was taking a rest there!

So there was only one fully alert(?) pilot for at least some of that flight. The other, sleeping(?), pilot probably not much use should a sudden crisis arise.

I am not suggesting that this happened in this instance, but it does seem to rather diminish the discussions of assumed crewing rules and practices in this thread.

4PW's

9th Jul 2009, 14:04

I believe one of two things happened: the plane crashed, or the plane did not crash.

Since the airplane has not yet been found intact, the plane did not crash.

This is a worthy contribution, almost as useful as this thread.

Long live aliens.

John47

9th Jul 2009, 15:23

PARIS (AP) — More than 600 pieces of Air France Flight 447 are being sent from Brazil to France by ship to be studied further for clues to the June 1 crash, Airbus said Thursday.
...
She said the material will arrive in mid-July and be examined at a Defense Ministry aviation center in the southern city of Toulouse — where Airbus is headquartered — by French accident investigators and judicial police.

The Associated Press: Remains of Flight 447 en route to France for probe (http://www.google.com/hostednews/ap/article/ALeqM5iOegnahAFcEgwJZ4WKGkVz9Dgq5wD99AVSG83)

Lengthy legal procedures in Brazil are slowing down a French inquiry into last month's Air France crash and Brazilian autopsy reports are still to be released, a French magistrate said on Wednesday.

French police sent by examining judges have visited the Brazilian institute charged with medical and legal examinations, but still lacked basic information related to Air France flight AF-447, which crashed into the Atlantic with 228 people aboard.

Authorities in Brazil have refused to hand their French counterparts the results of autopsies on 51 bodies, for example, as they had only begun so-called administrative proceedings and had not yet opened a formal judicial inquiry, he said.

"So from their point of view, they can't proceed with formal judicial cooperation," the judge said.

Brazilian delays slow Air France inquiry | World | Reuters (http://af.reuters.com/article/worldNews/idAFTRE5675ZL20090708)

lomapaseo

9th Jul 2009, 15:33

Re: The galley unit that was recovered - at some point this section left the aircraft through a hole/break that presumably was the same size or larger than the galley section itself.

Can this wreckage or any other of the pieces narrow the possibilities as to the type of impact with the water?

I believe it does. It supports the analysis of belly down and nearly flat with little forward speed.

I guess that this is what the prelimin report is also saying, but I can't read french.

But for me, I'm only interested in stuff happening at altitude for the time being.

Graybeard

9th Jul 2009, 15:50

Maybe Brazil wants to be paid for its search and recovery efforts.

Robin42

9th Jul 2009, 17:32

Graybeard:
Maybe Brazil wants to be paid for its search and recovery efforts Or maybe this particular judge just isn't really a judge but an anxious anonymous person interested in making the Brasilians looking silly. Everybody, but especially this supposed magistrate could know that the French police had four investigators present at the forensic examination of the 51 victims in Brazil. A judge, a magistrate, smearing the justicial authority of another country under conditions of anonymity, antic! If the French are in need for a scapegoat responsible for the delay which made the first French SAR Plane start at 12:30 on June 1, a delay which actually could have killed the last possible survivor, why don't they look for one at the ATC in Dakar?

einhverfr

9th Jul 2009, 17:34

One question out there for anyone who has done air-water collision investigation in the past is what impact do you think that wave height would have on the damage found in the crash debris? The A330 fuselage is about 20 ft wide, so if waves were 10 ft tall (and I would expect them to be substantially higher), they would seem to be quite significance on the forms of damage we would expect to see. But maybe someone has experience with this?

ArthurBorges

9th Jul 2009, 18:10

Qu'avez-vous vraiment changé depuis le très critique rapport Colin sur la sécurité aérienne ?

Je suis fier du rapport Colin, diffusé à tous les navigants de la compagnie, et qui montre que chez nous, il n'y a pas de tabous en matière de sécurité. En octobre 2005, nous avions confié à trois commandants de bord instructeurs d'Air France une mission d'analyse portant sur l'organisation et le fonctionnement de nos opérations aériennes. Depuis, il faut savoir que les recommandations de ce rapport ont été mises en œuvre dans tous les domaines : règles opérationnelles, organisation et sécurité des vols, formation des personnels navigants, exploitation et maintenance au sol.

Here's a human attempt at rendering the lad's statement, Lemurian:

What have you really changed since the highly critical Colin report on air safety?

I'm proud of the Colin report that was distributed to all our flight crews, and it shows that, in our company, there are no limits when it comes to safety. In October 2005, we asked three AF captain/instructors to do a study of the set-up and operation of our flight operations. You should know that since then, the recommendations from that study were applied across the board: operating procedures, flight safety & organization, flight crew training, ground maintenance and operations.

24victor

9th Jul 2009, 18:25

Here comes the cavalry....

Full story at www.nasa.gov (http://www.nasa.gov)

NASA Research To Help Aircraft Avoid Ocean Storms, Turbulence

Goal Is To Identify Rapidly Intensifying Storms

http://www.aero-news.net/images/content/aerospace/2009/NASA-meatball-logo-0908a_tn.jpg (outbind://110-00000000A5920FC51AFB4F4AB3C884FEE4219958E4B33300/#)NASA is funding the development of a prototype system to provide aircraft with updates about severe storms and turbulence as they fly across remote ocean regions.
Scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., in partnership with colleagues at the University of Wisconsin, are developing a system that combines satellite data and computer weather models with cutting-edge artificial intelligence techniques. The goal is to identify and predict rapidly evolving storms and other potential areas of turbulence.
"Turbulence is the leading cause of injuries in commercial aviation," said John Haynes, program manager in the Earth Science Division's Applied Sciences Program at NASA Headquarters in Washington. "This new work to detect the likelihood of turbulence associated with oceanic storms using key space-based indicators is of crucial importance to pilots."
The system is designed to help guide pilots away from intense weather. A variety of NASA spacecraft observations are being used in the project, including data from NASA's Terra, Aqua, Tropical Rainfall Measuring Mission, CloudSat and CALIPSO satellites.

24V

Razoray

9th Jul 2009, 18:29

welcome to the 21st Century!

:ok:

spagiola

9th Jul 2009, 18:48

Flight has more info from the interview of AF CEO Pierre-Henri Gourgeon, which is much more interesting that than the bits that have been cited here earlier.

Notably:
[AF559] crossed a turbulent area that had not been detected on weather radar and, as a result, increased the sensitivity - subsequently avoiding a "much worse" area of turbulence. ... The crew initially chose to deviate 20nm to the west but the radar then showed an extensive squall line which led them to deviate to the east by 70-80nm.

See Air France reviewing weather-radar use after AF447 crash: CEO (http://www.flightglobal.com/articles/2009/07/09/329492/air-france-reviewing-weather-radar-use-after-af447-crash.html)

WilyB

9th Jul 2009, 18:54

Or maybe this particular judge just isn't really a judge but an anxious anonymous person interested in making the Brasilians looking silly.

Reuters is probably part to this conspiracy. :rolleyes:

WhyIsThereAir

9th Jul 2009, 19:04

... combines satellite data and computer weather models with cutting-edge artificial intelligence techniques.

This is good stuff, but don't hold your breath waiting for it or you will turn blue and then several other colors while waiting. "Combine cutting-edge" in this context is code for "basic research". Basic research is good stuff, but optimistically it will take 5-7 years before it can become a product. NASA has been working on "Smart ATC" for some 10 years now and are doing good things; but I don't think a lot of it has made it into normal ATC usage yet.

But while this particular NASA plan will take a while to pay off, I'm sure there are very useful things that can be done immediately with not much more than a satcom modem, a laptop, and a little duct tape. A second generation version would build it into the ND. Pilots should probably get their unions to agitate for some quick solution like this, at least on long haul flights.

JuggleDan

9th Jul 2009, 19:42

I'm no lawyer, but I just wanted to make a quick comment about that:
Everybody, but especially this supposed magistrate could know that the French police had four investigators present at the forensic examination of the 51 victims in Brazil.
These experts were mandated by the judge in charge of the French penal investigation. They are thus bound by professional secrecy (penal code, article 11) and cannot communicate directly any information to the BEA. If I'm not mistaken, only the French judge may decide to make their reports public.

ArthurBorges

9th Jul 2009, 19:49

This is from a weeks-old interview with the AF459 captain and copilots, who all wish to remain anonymous. The original is at Le Figaro - France : «J'ai traversé le pot au noir20 minutes après le vol AF447» (http://www.lefigaro.fr/actualite-france/2009/06/23/01016-20090623ARTFIG00618-j-ai-traverse-le-pot-au-noir-20-minutes-apres-le-vol-af447-.php).

...

According to one of the two F/Os, “this cloud formation was hard to locate because there was no lightning.” AF459 made a 70nm detour while AF447, flying 20 minutes ahead, must have gone through that zone, the F/O added. However, his captain would not confirm that last point.

Pilot Error Unlikely
The AF459 flight crew noticed nothing unusual crossing the “black hole”. “Except for the cloud formation, flight conditions were normal and we heard nothing on the distress frequency. We also had no radio contact with AF447 before the accident, contrary to the rumor that has been going around for three weeks now.” Inflight, the captain had no knowledge of the disappearance of AF447. That part of the Atlantic is not covered by ATC frequencies that reach only 200 miles from the coast.

Approaching the Canary Isalnd, the AF459 captain established first contact with air traffic controllers. They asked him to make relay contact with AF447. “We radioed in vain on the distress frequency,” he said. “But we didn’t much worry about it because radio breakdowns on aircraft can happen. We also hoped another aircraft closer to its position might establish radio contact.”

The AF459 captain and crew first learned of the accident on arrival at CDG at 1135LT…The captain said human error was unlikely to explain the loss of AF447: “The preflight (=au depart) satellites photos were clear and any pilot knows how to use his radar.” If AF459 had managed to escape a particularly active cloud formation that was difficult to locate without increasing radar sensitivity, might AF447 have failed to increase it? “Sure, not everybody does that,” admits the AF459 captain.

Oddly, three weeks after the accident, the AF459 captain has not been interviewed by the BEA, which plans to publish its report at the end of the month. Contacted by Le Figaro, the BEA declined to comment on this point.

boguing

9th Jul 2009, 19:52

einhverfr

I'm a little bit qualified to answer that one.

Waves.

1/ Would make a controlled forced landing more gentle. Less friction/time. This is why seaplanes prefer a few ripples for take off. Nose down accident landing, with a nose into a wave face, almost infinite pressure loading on surfaces normal to that wave. Liquids are not compressible. Tail down 'landing' - waves wouldn't do much other than pull the nose down, perhaps violently (wave lengths and heights being just 'right')

2/ On floating bits of the aircraft. Any piece of debris with a Specific Gravity greater than 1, attached to a sufficiently large corresponding part with SG less than 1 will float. Wave action (cylindrical flow aligned normal to the wave peak) will have an effect on the piece. If the piece presents itself in the same direction to each wave (because it's shape vs wind/wave dictates that - a tall bit above the surface will keep that piece facing in the same direction wrt apparent wind angle, and or old wave train direction) then there will be repeated strains in a particular plane. If not, then there will be multiidirectional strains.

3/ If SG of the whole piece is less than 1, really very little damage through wave action.

4/ This applies to clothed bodies too. The heavier part is below the water, the wavelets will continually tug at loose bits thereto attached.

5/ At any angle of approach to water with a significant vertical speed you can treat it as concrete. Nose impacts, wings bend, engines off and tail at the end of the chain.

ps. The usual 45 degree thing applies. Hit anything square on fast enough. Terminal. At 45 degrees you might get away with it. Any less and you should buy a lottery ticket.

ArthurBorges

9th Jul 2009, 20:04

If I'm not mistaken, only the French (investigating magistrate) may decide to make their reports public.He'd better refer to his minister before opening his mouth on this one!

(For anyone unfamiliar with French Law, criminal investigations are headed by a magistrate. The idea is that, not being a police officer, s/he can evaluate evidence more objectively, thereby better protecting the suspect's rights. It also means that when the case reaches the prosecutor, the evidence and charges are neatly packaged and ready to serve in court. In the USA, police officers run the investigation independently and then move it directly to the prosecutor who sometimes grumbles when officers don't think in legalese.)

NARVAL

9th Jul 2009, 20:42

Thank you for the translation Arthur Borges! If Mr Gourgeon, Chief Executive of Air France seems to be very happy with his company (some people never learn) the Chief Executive or Air France-KLM, Mr Spinetta, told the shareholders today:
"Air France ne prétend pas «avoir tout bien fait» et la sécurité de ses vols «a été prise en défaut», a dit jeudi le président d'Air France-KLM Jean-Cyril Spinetta, en évoquant les circonstances de l'accident du vol AF 447 entre Rio et Paris le 1er juin."
I translate before you (sorry!):
"Air France does not say it has done everything well, and it's Flight Safety has failed."
Seems to me the days of Mr Gourgeon as Chief Executive will not see autumn...

24victor

9th Jul 2009, 20:43

This is good stuff, but don't hold your breath waiting for it or you will turn blue and then several other colors while waiting. "Combine cutting-edge" in this context is code for "basic research".

Very true, right on the "bleeding edge".... They'll be looking for partners to fund the move to production no doubt and this time they might get some from Collins, Honeywell, L3, et al. NASA themselves cannot take the development through to certification.

The base technology is there. Look at any Cirrus avionics fit - Garmin G1000 and Sirius/XM weather overlay provides most of what's needed for "phase 1" if the satellite data is available for the area in question. Storm tops and intensity would be a start. Forecasting CAT might be better off left to on-board Doppler for now (IMHO).

Rgds.

24V

SaturnV

9th Jul 2009, 21:32

Arthur Borges,

It would seem from the BEA report that the AF459 crew was interviewed prior to its publication. There is an extensive narrative of the deviation flown by this flight, and their communication with Atlantico in that regard.
_______________________
LH507 preceded AF447 at ORARO by 20 minutes (or about 0143). LH507 deviated west by 10 NM. (This may be the flight that was providing AMDAR reports. If not, the flight with AMDAR preceded LH507 by 10 minutes.)

IB6024 was at ORARO 12 minutes after AF447. IB6024 deviated to the east by 30 NM.

AF459 initially chose to deviate west by 20 NM, but then deviated to the east by 70-80 NM. AF459 was at ORARO 37 minutes after AF447.

AF447, instructed to contact Atlantico at INTOL, establishes contact with Atlantico at 0133-0135. How likely is it AF447 overheard LH507's deviation west? From the radio communication transcript, there is no indication that AF447 and Atlantico discussed the weather between ORARO and TASIL. Nor does the transcript contain (other than one or two references) the radio communications between other flights and Atlantico, say between 0100 and 0300.

Triskel

9th Jul 2009, 22:06

Taking the concensus that CB clusters in the ITCZ may well have been at least a contributory factor in the loss of AF447 - since there are daily trans-Atlantic tracks promulgated in relation to jetsreams - would it be beneficial to develop a similar track forecasting system for trans-hemispheric flights to avoid significant active areas of the ITCZ? (each area of ascending air has an area of generally descending air not too far away - reasonably predictable at least on a scale of several hours).

Art-Deco

9th Jul 2009, 22:51

In my prevoius post (page 162 / message 3234) is suspected that the rain and hail attenuation would be the cause of the lost 31 seconds of ACARS-txm:s. JD-EE replied on page 164 /message 3263 that it only could be possible IF the A/C already had diverted to a lower flightlevel.

To be sure that the figures was right in this matter, I started to do several "link-budgets" to the Inmarsat bird that is in geo-position (=fixed service). As transmissions on this latitude is nearly straight up, the rain-attenuation is approx 8 times worse than having the same situation above Paris/France for example.

While I made these calculations and checked the equipment on this flight, I made a cruel discovery, I therefore ask all aviation experts here to have a close look at my findings and please replay if this could be the "missing detail".

When calculating the attenuation I got a max of approx 18 dB:s that could make the L-band carrier lost temporary for the satellite, but this only if the flight had diverted to a lower flightlevel around approx 15.000 feet.
But the real suprising fact is that the Satocm unit of EMS 3800 has limit of 530knt/mach 0.95 with max pressure of 4,5kPa. I then suspected that there was a chance of the Satcom-dome getting "ripped-off" in high speed, and if that was the case, there should be a 50% chance that the dome would slam into the a/c - vs and leave a impact trace.

So I checked on the 2 first photos from the rodder pictures in the water and compare with the Paris may 31st photo, and indeed, there is a quit big impact trace on the rodder that would match the size of the dome from the cockpit.

http://i832.photobucket.com/albums/zz243/art-deco/acarsattintol.jpg

http://i832.photobucket.com/albums/zz243/art-deco/VScompare.jpg

Old Carthusian

9th Jul 2009, 23:17

Quite simply the reason why BEA hasn't got the autopsy reports yet is bureaucracy. Some small official is insisting that the exact procedures are followed. It happens everywhere and especially when two different jurisdictions are involved.

p51guy

9th Jul 2009, 23:31

Triskel, When they got to the problem area was about 4 hrs after their last land briefing so everything would be different then. If you mean transmit them up a picture of their route and the satellite info by all means do that if possible. It is possible if they pay for the capability. Most airlines now discourage use of satcom because of the expense. More than likely their onboard radar if used properly would have given them even a better picture of what they were dealing with. If the captain was on his rest break the two remaining pilots were running the program and radar.

Hyperveloce

9th Jul 2009, 23:34

A contribution by Pilotaydin, on the Airliners.net forum (Pitot freezing=>overestimated airspeeds=>nose up=>stall):
____________________________________________________________ ________
I would like to share a small story about something i experienced in the sim a while back, as a demo from my instructor towards the pros and cons of fbw and envelope protection...

we "flew" through an area of icing in the sim, the probe heat function and the airbus a/c itself is designed to fly through known icing, however, that doesn't mean it can withstand anything put in its path... our pitots iced over and our airspeeds started indicating 300+ at high altitude, which is bad news, because we're passing Mmo and Vmo, so the a/c as per design pitched up.... after about 20 seconds of this, as the speed wasn't decreasing, we were actually stalling and losing altitude, and the sidestick = useless, it wouldnt let any one of us pitch down, we started a large rate of altitude loss. Even if we disconnected the a/thr system and idled or added full power, the damn nose was pitched up....we went down 30,000 feet into the water outside jfk in the sim....during that descent, nothing came up on the ecam, just the warning chimes of overspeed.......we of course didnt just sit there, it was a demo we were observing he different things going on...at one point my hand did go up towards the PRIM 1 and PRIM 2 computers...i thought maybe if i let them out of the loop, we could go to altn law but i decided not to intervene to see the outcome....
knowing your systems helps, and the a/c doesnt always provide an answer to us....

Things need interpretation and over automation sometimes leaves us out of the loop...the other day over the atlantic, at 35,000 feet, we got master caution chime that said :
Start valve open and it asked us to switch off the bleed to one engine....leaving us with only one bleed left over the atlantic....are you gonna follow the ecam? or are you going to emergency cancel it? :)
____________________________________________________________ _
btw, I don't get how a Pitot obstruction only (of the ram port/the drain) can lead to overestimated airspeeds (and possible overspeed alarms): if the dynamic pressure cannot be overestimated (?), then it has to be the static pressure which is underestimated (?) and this would imply that the static ports are also blocked and that altitude has been lost since their blockage ? Is that so ? Would there be other ways to overestimate airspeeds ? On the contrary, a blocked Pitot ram port is sufficient to roll back the airspeed to 70-80 kts.
Jeff

takata

9th Jul 2009, 23:37

p51guy:
If the captain was on his rest break the two remaining pilots were running the program and radar. I still have found no information of the experience of these two pilots. Why?
Laziness?
What do you want to know about them you can't read in the preliminary report?
S~
Olivier

Graybeard

9th Jul 2009, 23:49

Pitot probes have a liquid drain (bleed) hole, whose air bypass has to be accounted for in the airspeed calcuation. Clog the drain, and pitot pressure rises, giving erroneous high airspeed. Indeed, per reading in this thread, some of the earlier Airbus pitot malfunctions were with poorly manufactured drain (bleed) holes.

Add more ice, and you clog the pitot head itself, and then pitot pressure will lock, or will decrease if there is any drain opening at all.

GB

Graybeard

10th Jul 2009, 00:09

As posted earlier, the head of AF is wondering aloud if the crew of 447 had not operated the Wx radar in a way to see the storm they must have flown into.

Spend $200 Million for a new airplane, but not $200.1 Million for one with the latest and greatest Wx Radar. . Why? Because the 25-30 year old technology Wx Radar meets the minimum requirement for airworthiness. Besides, you would have to re-train the pilots (if they get any Wx training now), and retrofit the rest of that type fleet.

The "new" (~7 year old) multi-scan Wx radar would have had a far better chance of accurately displaying that storm system to the pilots. Weather radar operation and interpretation is one of the few pilot tasks that haven't been automated. Why not spend a few extra bucks and give pilots the best tools available?

GB

takata

10th Jul 2009, 00:17

Graybeard:
Pitot probes have a liquid drain (bleed) hole, whose air bypass has to be accounted for in the airspeed calcuation. Clog the drain, and pitot pressure rises, giving erroneous high airspeed. Indeed, per reading in this thread, some of the earlier Airbus pitot malfunctions were with poorly manufactured drain (bleed) holes.

Add more ice, and you clog the pitot head itself, and then pitot pressure will lock, or will decrease if there is any drain opening at all.Hi,
I'm with Hyperveloce on this one. Considering the drain's hole dimension (I've got this detail somewhere) which is very small on Thales probes, an overspeed would be barely noticeable and certainly won't reach this 20-30 kts overspeed range that this simulation would imply (maybe only few kts at max). When drains are blocked, ice will build up much faster because turned into water by the probe heaters, then the pressure will be under reported.

S~
Olivier

Hyperveloce

10th Jul 2009, 00:45

I see GB, indeed, with both the Pitot tube ram air and the drain blocked, a machmeter should work like an altimeter, largely overestimating the airspeed if altitude increases (seems in the order of +40kts/+1000ft @FL350). But if altitude remains constant, it can't be an overestimation ?
Jeff
PS) following an accident wich began by Pitots freezing, obstructed or polluted Pitot drains were found on a large fraction (~20%) of the French fleet of Mirage 2000 (with a high probability of occurrence, ~70%, in humid/hot areas). the quality of the manufacturing was also a problem for a fraction of them.

Graybeard

10th Jul 2009, 00:51

OK, guys, maybe you can explain the overspeed warning had by the NW A330 into Japan recently? The static ports haven't been implicated, just the pitot probes.

I suspect it's not just the size of the bleed orifice compared to the main one, but also its alignment. If it is at right angle to the airstream, it will draw a vacuum, meaning that it is a much larger factor than mere size relationship.

Rananim

10th Jul 2009, 00:59

It's not important how they crashed but why.

http://boeing.com/commercial/aeromagazine/articles/qtr_4_07/AERO_Q407_article3.pdf

These additional conditions are also typically
found during engine ice crystal power-loss events.
■ No pilot reports of weather radar returns at
the event location.
■ Temperature significantly warmer than
standard atmosphere.
■ Light-to-moderate turbulence.
■ Areas of heavy rain below the freezing level.
■ The appearance of precipitation on heated
windshield, often reported as rain, due to
tiny ice crystals melting.
■ Airplane total air temperature (TAT) anomalyreading
zero, or in error, due to ice crystal
buildup at the sensing element
■ Lack of observations of significant airframe icing.

Convective clouds can contain deep updraft
cores that can lift high concentrations of water
thousands of feet into the atmosphere, during
which water vapor is continually condensed
and frozen as the temperature drops. In doing
so, these updraft cores may produce localized
regions of high ice water content which spread
downwind. Researchers believe these clouds
can contain up to 8 grams per cubic meter
of ice water content; by contrast, the design
standard for supercooled liquid water for
engines is 2 grams per cubic meter.

Another possibility that some have mooted on the internet is that the aircraft was being blown around a lot in severe to extreme turbulence, but I don’t see how thereby one would get discrepant readings: rather, all probes would vary wildly, but coordinated, as individual gusts hit all three at more or less the same time. So I really don’t see that as a plausible reason for the P-S system issues. Ladkin

Severe icing alone overwhelming the sensor systems, though, does not by itself lead to an accident. The AC could be controlled with pitch and power, and the Aircraft Operating Manual explains exactly what pitch and what power setting in some detail, if one has an “ADR disagree” warning.

Ladkin

“Of several acceptable explanations for a phenomenon, the simplest is preferable, provided that it takes all circumstances into account.”

Occams Razor Theory

Multi-sensor blockage combined with dual flameout?Doesnt this fit like a glove with the least assumptions(ie.just one assumption:high-alt ice crystal icing alone ) and no contrivance(experienced crew flew into cb etc).Its been posited before I know.Is it a match for the ACARS messages,esp the last advisory re cabin alt?ie CPC affected by flameout/stall/surge prior ACARS disabled due total main AC outage?
Im just thinking that all this talk of control laws,jet upset,wx radar gain/tilt/brightness,rudder etc may be too convoluted and unnecessary.

A 22h22 et45s,les "ENGINE ANTI-ICE" sont places sur "ON"
Air Caraibe report
This was the first pilot action in response to the weather phenomenon they experienced that night and occurred only 9 seconds after the TAT registered -5C and 14s before erroneous airspeed.

ttcse

10th Jul 2009, 01:07

RananimIm just thinking that all this talk of control laws,jet upset,wx radar gain/tilt/brightness,rudder etc may be too convoluted and unnecessary.Your double-flameout is less convoluted only because you ommited the 'and then.....'.

takata

10th Jul 2009, 01:26

Graybeard:
OK, guys, maybe you can explain the overspeed warning had by the NW A330 into Japan recently? The static ports haven't been implicated, just the pitot probes.

I suspect it's not just the size of the bleed orifice compared to the main one, but also its alignment. If it is at right angle to the airstream, it will draw a vacuum, meaning that it is a much larger factor than mere size relationship.Difficult to take NW incident as an example as very few details are actually available yet. It is missing most of the details: "large airspeed fluctuations, small altitude fluctuations, and an overspeed alert." That's all.
It looks like the fluctuation is due to sequential probes clogging/cleaning/clogging... then, at some point, over-pressure also. But from all other more detailed reports, when the probes are blocked for few minutes, the speed is always under-reported. And it is very difficult to know exactly where and how they were blocked as, once landed, no ice remains. The same issue is reported from laboratory test as it is difficult to re-create some unknow conditions in order to simulate and study this particular failure.

S~
Olivier

safetypee

10th Jul 2009, 01:35

Graybeard, (# 3409) IIRC it was static pressure that was implicated – altimeter fluctuation.
But does the altitude computation have an airspeed correction for static error proportional to speed?
If so, then static pressure need not be considered.

vapilot2004

10th Jul 2009, 01:41

Hyperveloce:

The situation as described in the real world would have brought at the least an ADR Disagree and would require cross checking your AOA and A/S data. Meanwhile, the prudent gents would have their eyes on the indicated altitude & VS during all of this and adjust the pitch and power appropriately.

The story credited to "pilotaydin" lays out an uncertifiable behavior for any aircraft. I say the sim was unrealistically programmed, likely on how pitot/air data failure modes were setup.

To go back to AF447, an ADR disagree/unreliable airspeed at that altitude, in moderate to severe turbulence and possible vertical air currents, could be a tough nut to crack on any aircraft, flight envelope protections properly working/fitted/designed or not.

HarryMann

10th Jul 2009, 01:50

Rananim

Indeed, a sequence to consider?

Some things are on your side
No real evidence of 'extreme' turbulence in that area (others avoided it)
Combined effects of Flight Instrumentation/degrading systems AND engines tp diagnose/respond to e.g even higher cockpit workload

You would have to make a case for:

No Maydays, ELT
Inability to re-start lower down
What ACARs tx this would or wouldn't have generated

Are you suggesting the combined effects of lost FI and thrust loss would have created a rapid stall/upset?
Or a gliding descent into possibly worse conditions?

takata

10th Jul 2009, 01:52

ttcse:
Your double-flameout is less convoluted only because you ommited the 'and then.....'.

I'll try it:
When the pitots-probe/TAT were assumed frozen by the pilots, they would have read in the QRH that any "stall warning" should be respected. As they experienced undue stall warnings from the begining of the sequence, without noticing any buffeting nor decreasing aerodynamic noise; they decided to ignore it. But, in order to keep a safer margin, they decided to reduce their altitude, just in case. Thrust was set to idle for a safe descent, and then, an engine flameout occured because some very small ice particules in this saturated Anvil had accumulated over the engine for a too long time.

S~
Olivier

takata

10th Jul 2009, 02:03

HarryMann:
You would have to make a case for:
No Maydays, ELT
Inability to re-start lower down
What ACARs tx this would or wouldn't have generated1. No Maydays heard, doesn't mean they didn't try; radio com problems reported all over this zone (weather?) and radio problems with this particular aircraft.
2. or engine refight too late. The process is not easy, based on speed and altitude which will lack in the first place; need to troubleshoot many other problems at the same time; need to make distress call with unreliable radioset due to lack of main power.
3. NIL...no more ACARS in case of double engines flameout.

S~
Olivier

lomapaseo

10th Jul 2009, 02:19

1. No Maydays heard, doesn't mean they didn't try; radio com problems reported all over this zone (weather?) and radio problems with this particular aircraft.
2. or engine refight too late. The process is not easy, based on speed and altitude which will lack in the first place; need to troubleshoot many other problems at the same time; need to make distress call with unreliable radioset due to lack of main power.
3. NIL...no more ACARS in case of double engines flameout.

You can't push a theory unless you also consider the cons against the theory.

But just to keep the discussion alive, give a thought to what happens to the flight after the engines flame out and ACARS goes off line with nary a clue that the individual electrical generators preceeded it.

takata

10th Jul 2009, 03:06

lomapaseo:
You can't push a theory unless you also consider the cons against the theory.Sure, but 99.99% of this thread is only about the cons against this theory. The basic cons are just that we don't know what happened for sure and it will be really difficult to prove anything without finding the FDR/CVR. But we also need to use the few facts we already have and be able to fill the huge gaps in between.

Rananim basically used what we know for sure: ice was there and certainly in enough quantity to make something ugly to happen to engine like in certain cases already seriously studied because it could harm any one of the most modern engines (there is plenty of papers about severe icing, at previously unknown levels, during the last four years as it appears to be an increasing threat for high flights above tropical weather - read what NW pilots said about the conditions they met in Japan).

But just to keep the discussion alive, give a thought to what happens to the flight after the engines flame out and ACARS goes off line with nary a clue that the individual electrical generators preceeded it.ACARS should not report flameout because it takes some time to trigger an ACARS and no time to switch to EMER ELEC once engine flameout. Then Satcom will go off-line no matter if any ACARS is on the pipe.

What happens then? with an unreliable airspeed, altitude, direct law, etc. The pilots will be busy for quite some time in order to sort things out. They'll need to maintain 300 kts for a refight, one engine at a time. At this speed, they would be at sea level in less than 15 mn. Considering they'll have no reliable airspeed until much lower, they could have missed the conditions and ended too low. Then hit the water (it's night and certainly under heavy rain) in an attempt to refight an engine. For example, hitting hard with the tailcone when making a ressource, killing horizontal energy, then pancacked. Another possibility will be a stall at low altitude after such an attempt, successfull or not.
The other point which make me think this kind of scenario a serious possibility (flameout) is that I'm pretty sure they turned back: if not, it is just not possible to reconciliate the actual drift of the wreckage with any fast upset at altitude.

S~
Olivier

ttcse

10th Jul 2009, 03:23

takataWhat happens then? with an unreliable airspeed, altitude, direct law, etc. The pilots will be busy for quite some time in order to sort things out. ... I wasn't arguing against power failure, but against the notion that it would offer an even simpler Occams Razor. To make my point I was fishing for the 'What happens then?"

The other point which make me think this kind of scenario a serious possibility (flameout) is that I'm pretty sure they turned back: if not, it is just not possible to reconciliate the actual drift of the wreckage with any fast upset at altitude.I would like to re-offer another theory on crash point, debris drift, and course deviation.

To cut to the chase, they came down west of course but near the zone of eastward current flows. Then they drifted eastward/east-north-eastward before then currents took debris more north-north-eastward. Somewhere in the interface between the eastward zone and what's north of it is a region of very slow moving current. Just to put that card on the table as a potentially valid thing.

philipat

10th Jul 2009, 03:28

takata

10th Jul 2009, 04:39

ttcse:
I wasn't arguing against power failure, but against the notion that it would offer an even simpler Occams Razor. To make my point I was fishing for the 'What happens then?"I know you didn't but also most people don't really understand what is the real meaning of this overused reference to Occams Razor "law". In short, it means that the simpliest explanation which agree with all the facts is certainly the good one. The difficulty behind this theory is much more about understanding all the facts than putting them together into the simpliest explanation possible.

For most people here, the simpliest interpretation of the end at 0214 of ACARS is to say: obviously, no more ACARS = aircraft crashed. This is a fact and lets build a theory starting with this postulat without even verifying if another possibility exist. But this is not the only possibility as no more engine imply no more ACARS also.

Another example was the severe/extreme turbulence theory which postulate: proximity with an active CB = severe turbulences. Then, because this aircraft was experiencing severe turbulence at 0210, it could have been only worst later, consequently it crashed at 0214. Until one say: "hey, at 0210, the autothrust setting doesn't fit with severe turbulence from Air France SOP and, by the way, the initial report of turbulence has never been confirmed by the BEA. Why do you always mention turbulences when the only factor confirmed about the weather is ice?"

And so on.
If the criminal investigators used this Occams Razor principle the same way to arrest people, they would always arrest inocent people which looks like criminals rather than criminals which looks like inocent people. As I said, the main difficulty is to find what are the real facts and to cross-check everything before building "simple" hypothesis based on unverified postulats. Others will start from their own conclusion and then will try to bend any relevant fact around, no matter if others doesn't fit at all.

To cut to the chase, they came down west of course but near the zone of eastward current flows. Then they drifted eastward/east-north-eastward before then currents took debris more north-north-eastward.An approximate distance crash and zone with a map will explain it much better.
If you based this claim on OSCAR, let me tell you that this is a good tool for an average zonal current but in no way it should be considered as an ultimate reference for such a study as it is based on sattelite data extrapolation. See the validation method here compared to drifting buoys and the limitation in the granularity of the dataset (about 20 days average mean with filtering):

Method:
In these comparisons, as in the rest of the validation study, the drifting buoy data are minimally processed. The principle of this validation study is to compare OSCAR to the drifter data at the locations of the buoys.

For each individual buoy, the drifter data (locations and derived velocity vectors) are initially sampled every 6 hours, and are 20-day low-pass filtered along the drifter trajectory. Hence this validation study only concerns surface current variations on time-scales on the order of, or larger than, 20 days. This is consistent with the OSCAR surface current processing, which, by construction, is relative to periods larger than 10-20 days. The filtered drifter data are then sub-sampled onto the ~5 day OSCAR time base. For a set of drifter vectors defined by locations, times and velocity components, the collocated OSCAR vectors are obtained through linear interpolation at the same locations. The two collocated datasets can then be compared. Moreover, the actual drift is not a simple function of surface currents. Drift may be approximated by buoys but it is related to the drifting object (the reason why, after several days, a wreck field will be 10 time larger than it was the first day, because objects are drifted differently. The main components of a drift vector are the near surface currents and the surface winds (here waves height may be neglicted) which are function of the object.
I did something much simplier than that. I reconstructed the real drift from 6-10 June (0.37 m/s, hdg 357 deg). then, I compared it to different currents maps (including OSCAR) to check versus the zonal currents and for extracting the wind factor during that period. The main purpose was to get an approximation of the distance covered during 1-5 June which is in the range between 90-115 NM. I'm still working on the wind part to have a better estimation of the distance and direction. But between 1-10 June, all the objects have to come closer and end at roughly the same place. From your estimation, I just can't understand how it is possible.

S~
Olivier

ArthurBorges

10th Jul 2009, 04:49

If Mr Gourgeon...seems to be very happy with his company (some people never learn) ... Mr Spinetta...

Narval, when Mr. Spinetta was appointed to head Air France over a decade ago, nobody there or at Air Inter, the domestic carrier, expected him to last very long. The job was a political plum that came on plush one- or two-year ejection seat and he turned it into a real job. From your pseudonym, I infer you already know this but it might be news to at least some readers here.

Reports of his speech at the AF/KLM annual general meeting reflect his ability to communicate sincere sober emotion along with the frank statement "We were caught out on safety."

On Mr. Gourgeon, the same interview which has been served up here in bits and pieces contains another morsel:

Pourquoi ne pas être allé immédiatement au Brésil ?
Je ne suis pas allé immédiatement au Brésil pour pouvoir assister à la cérémonie en hommage aux victimes à Notre-Dame de Paris. Le lendemain, j'étais à Roissy pour le rassemblement en mémoire des douze membres d'équipage et de quatre autres salariés disparus dans le vol AF 447. C'était très émouvant, il y avait 10 000 personnes. Le silence était total. Le moment très difficile. Nous avions la mission d'amener nos passagers à bon port et nous ne l'avons pas fait. Chacun pense dans la compagnie : «Air France, ce n'est pas ça». La charge émotionnelle est immense. Quant au Brésil, j'en reviens. Là-bas, le 30ème jour après la disparition d'un proche est un jour de deuil très important. J'y étais. Les familles que j'ai rencontrées en étaient très touchées.

This obtains:

Why didn't you go out to Brazil right away?
I didn't go right out to Brazil so I could attend the memorial service for the victims at Notre Dame Cathedral. I was at Roissy (Airport) for a ceremony to commemorate the 12 crew members and four other AF staff lost on AF447. It was very moving; there were 10,000 people. There was total silence. It was a difficult moment. Our mission was to deliver passengers to destination safely and we didn't do that. Everyone in the company was thinking: 'This is not what Air France is about.' The atmosphere was heavy. Getting back to Brazil, there, the 30th day after someone passes away is a very important day of mourning. I was there. It was very touching for the families I met.

Looking at the whole interview, I'd qualify Mr. Gourgeon's attitude as defensively shaken, responding with a barrage of detail to project an attitude of transparency. Another question was about the rumor of a spate of cabin crew resignations, which he took as an insult to the commitment of AF staff, adding that "not one" had opted out. A preceding question asked about delays in contacting victims' families. He just said nobody asks you for your next of kin anymore when you buy a ticket, you just indicate your mobile phone number: "But obviously the mobile phones were with the passengers."

On a last detail, Spinetta chairs the AF/KLM board; Gourgeon is AF/KLM CEO.

vapilot2004

10th Jul 2009, 05:39

The Mods do a remarkable job of staying on top of such a fast moving thread. I wonder if it might be desirable/feasible to delete posts without automatically re-numbering the thread? This would then make references to earlier post numbers in message text easier to locate (And would also provide a measure to the reader of how much cr*p gets deleted!)

Philipat, the numbering scheme may be a limitation or setting of the board software. There is a permalink at the upper right hand corner of each post that lives up to it's name and will always connect to a post still up.

I agree with you. Sometimes posts are more than a page or two away from their original location due to all of the bad that requires Mod Pruning.

wilyflier

10th Jul 2009, 10:17

Extreme "outside normally expected maxima" of atmospheric high altitude water/fine ice content has been quantified elsewhere recently . I recall 4 times previous accepted figures
.Does a double engine ice event and subsequent controlled descent actually fit all the ACAS signals without further complexity.?
(Silly me, didnt note the web source)

WhyIsThereAir

10th Jul 2009, 11:25

Does a double engine ice event and subsequent controlled descent actually fit all the ACAS signals without further complexity.?

Does an engine flameout from icing make an ACARS message of any type? If so, is it a failure or a warning message? Is there a cockpit flag or indicator if an engine flames out? If so, it might make an ACARS warning message.

We know that ACARS can't send after both engines are down. But it appears that it should be able to send if only one engine is down.

If an engine down creates a failure message (and only a failure message), and both engines go down within less than 60 seconds of each other, then we would not see the failure because failures are held for 60 seconds, and the AC1 bus might have gone down before the close of the window.

On the other hand, if an engine down causes a warning message, or causes a cockpit flag or indicator that would be reported with a warning message, then since warning messages are sent 'immediately' (within a few seconds, normally) then I'd expect to see something about one or both engines going down before power to the ACARS data chain was lost.

JenCluse

10th Jul 2009, 12:11

. . . this was up and running back then . . .

Satellites get the jump on storm prediction (http://www.gizmag.com/predicting-storms-with-satellites/12180/?utm_source=Gizmag+Subscribers&utm_campaign=bb62132455-UA-2235360-4&utm_medium=email)

. . . but hopefully it's not too far off.

DJ77

10th Jul 2009, 12:24

Spend $200 Million for a new airplane, but not $200.1 Million for one with the latest and greatest Wx Radar. .

Is that aimed at Air France ? Do you know something that we don't ?

And, Multiscan radar is not the panacea that you seem to believe. I often had a much better picture scanning manually, playing with gain when needed. The reason appears to be that auto scan mode systematically uses ground clutter suppression (GCS). GCS is effective, but it also supresses a lot of real weather returns.

NARVAL

10th Jul 2009, 12:26

Narval, when Mr. Spinetta was appointed to head Air France over a decade ago, nobody there or at Air Inter, the domestic carrier, expected him to last very long. The job was a political plum that came on plush one- or two-year ejection seat and he turned it into a real job. From your pseudonym, I infer you already know this but it might be news to at least some readers here.

Quite right ArthurBorges. It happens that I know Mr Spinetta personally, for reasons outside the aviation subjects. He is at the very least,honest. And he attended too many funerals not to be truly shaken by this accident. Mr Gourgeon has been for some time with Air France, but has a difficult position as he was a former chief of the DGAC and among other decisions was the certification authority for the A330. He often says to journalists "I am not an expert in technical matters..."That deserves to be taken as what the British call an understatement.

ArthurBorges

10th Jul 2009, 15:30

I think we know the same set of interlocking networks. We crossed pedestrian paths at GARD, which he presided before rising to his current level of eminence although even then my face was worth only his nod, a smile and a handshake.

Still, I am sure he was shaken.

I am equally sure that Mr. Gourgeon was equally shaken.

Is there ego in it?

Yeah.

But it's still sincere.

As pedestrians, we do what we can with what and who we are.

(To moddies: this is OT and I apologize -- please make an exception just this once)

Dutch Bru

10th Jul 2009, 16:07

It is at least interesting that despite the BEA report of August 2008 (a study on turbulence/weather related upsets, including with AF long distance a/c) there was apparently so far no hightened awaress on the use of weather radar. Link to the report in post # 800. This study pinpoints amongst others to weaknesses in the operation of wx radar by f/c's.

It is BTW interesting that the report mentions one (AF) accident with an A340, where the captain was not on the f/d when a serious upset happened (overspeed, A/P disengage) and where the PF was unable to open the door for the captain to re-enter until after the upset, since the PF needed to regain control over the flight.

The report also states that it would make sense that ACARS is used more for companies and crew in flight to communicate weather updates. In the case of AF447 the f/c nor AF did make use of this possibility.

Fact is that there would have been quite some reason for that. The TEMSI file on board showed ISOL and EMBD thunderstorms en route and so did the SIGMET 7 for FIR ATLANTICO, valid from 1800-2200, as mentioned in the prelim report indicating EMBD TS.

What is interesting of the prelim report is that it seems to mention SIGMET 10 for FIR ATLANTICO as the next SIGMET. While this is true in terms of period of coverage (2200-0200), the prelim report does not mention SIGMET 8 and 9.

SBAO SIGMET 8 VALID 311800/312200 SBRE- ATLANTIC FIR EMBD TS FCST SW OF CIDER PSN/ S35W034 AREA TOP FL400 STNR NC=

SBAO SIGMET 9 VALID 312200/010200 SBRE- ATLANTIC FIR EMBD TS FCST SW OF REGIS PSN/ERETU PSN/ N02W046 AREA TOP FL370 STNR NC=

Combined in a series 7 to 10, the SIGMETs show highly dynamic, intense and widespread EMBD TS activity in the ATLANTICO FIR on the foreseen route. Had the AF447 f/c availed about the full series through ACARS, they could probably have been on higher alert as to penetrate the zone concerned and perhaps used the wx radar more optimally.

Rananim

10th Jul 2009, 16:34

loss of both engines does not cause an immediate loss of pressurization, nor does it even result in a high cabin rate of climb. By the time any significant cabin rate of climb obtained, the capability of sending ACARS messages would have long been lost).

PJ2(page 143)

What if rollback or stall preceded flameout?GCB still closed but bleed flow to packs disrupted to trigger the last ACARS.

As to the "what then"...well,I dont think the lack of any distress call is too big an issue considering where they were.The lack of LJ's?Failure to re-light?Bodies were found with no clothing.If bodies had been found clothed but with no LJ,yes.Re-light requires flt envelope check which requires reliable instrumentation.Dark night,bad weather etc.Relights folllowing crystalline icing are 100% from what Ive read so yes its still a tenuous theory.

PJ2

10th Jul 2009, 16:38

Dutch Bru;
Combined in a series 7 to 10, the SIGMETs show highly dynamic, intense and widespread EMBD TS activity in the ATLANTICO FIR on the foreseen route. Had the AF447 f/c availed about the full series through ACARS, they could probably have been on higher alert as to penetrate the zone concerned and perhaps used the wx radar more optimally.
Flight crews avail themselves of ACARS met reports all the time. In my experience, company dispatch provided timely and up-to-date information on SIGMETS as a matter of flight following, a legal and operational requirement in many states. Most crews would plot the SIGMET'd area on their planning charts then keep a wary eye using all available techniques including radar. That is not where the problem lies. The problem is in teaching how to use the radar "optimally". Likely, most pilots pick up the use of their radar through "osmosis", which does not filter misunderstandings and shortcomings in knowing one's equipment.

Rananim;
What if rollback or stall preceded flameout?GCB still closed but bleed flow to packs disrupted to trigger the last ACARS.
Sorry, do you mean "stall" of the engine or of the aircraft? I'll assume engine for now, :). A stall of the aircraft at that point, (powered), would generate ACARS messages, and we see none.

Logically, this scenario, (engine rollback/stall, then cabin pressure message) can't work because there would (likely, but not necessarily) have been messages indicating engine "failure". It depends - the word "rollback" means the inability to accelerate the engine but it's still turning, burning and hydraulic-ing - so the possibility, (but not the probability) is there.

As to the "what then"...well,I dont think the lack of any distress call is too big an issue considering where they were.It is not an issue at all. Those who are either confused by the absence of such a call or are mildly chiding/merely "observing" the absence of a call don't understand the swiftness of what happened in the cockpit and what ensued. The crew would have been struggling to maintain situational awareness and discipline in a very serious, rapidly degrading circumstances. The judging of this absence is therefore wholly inappropriate; even the notion that an "automatic" distress call could be sent is naive.

The lack of LJ's?Failure to re-light?Bodies were found with no clothing.If bodies had been found clothed but with no LJ,yes.Re-light requires flt envelope check which requires reliable instrumentation.Dark night,bad weather etc.Absence of any life-jackets in use is evidence for swiftly overwhelming events in which there was no time to prepare for the emergency.
Relights folllowing crystalline icing are 100% from what Ive read so yes its still a tenuous theory.
I fully agree. Just to be clear, it is not my theory, nor do I support the view that the engines flamed out due to ice crystals. The 330 has flown thousands of hours through "ice crystals" in high altitude layers without result. I've flown in "ice crystals" throughout the career without result in terms of engine roll-back or upset.

To recall the point, if the aircraft lost sufficient speed to enter a stall and the BEA has concluded that impact was of a flat aircraft attitude, high-velocity, vertical trajectory nature, then I submit that due to the very high angle of incidence in such a trajectory, the engines would have flamed out. I submit that the ACARS cabin advisory message was due to the effects of degrading upstream monitoring processes rather than a compromise of the cabin structure at that point or the loss of bleed-air input into the cabin to maintain pressurization. The BEA report does not comment on this message and so it is entirely conjecture.

SaturnV

10th Jul 2009, 16:47

AP RIO DE JANEIRO – An American colonel says two ships searching for the black boxes of Air France Flight 447 are ending their hunt.

A French nuclear submarine is continuing to look.

U.S. Air Force Col. Willie Berges is the Brazil-based commander of American military forces supporting the effort. He says one ship towing a U.S. Navy listening device stopped searching Friday.

He says the other ship towing a device will end its search within hours.

Berges says the ships had "no success."

Time for the side-scan sonar.

xcitation

10th Jul 2009, 17:04

Anyone know what the major airline policies/guidance are for deviation due to weather?
The IB flight leaving 10 minutes later presumably had the same pre-flight weather data as AF447. They chose to load extra fuel (I recall 4000 gals) and a wide deviation around the large multi-CB weather system.
Curiously a LH flight and another AF flight the captains chose to try to pick a hole through the weather system.
Is it a question of the captain filing a flight plan and it is never reviewed or questioned? Or is there some feedback/friendly advice from the airline.
I am trying to understand the factors that influenced IB captain to opt for a very safe wide deviation pre-flight whereas other flights chose a path through it. Perhaps the flight plan process could be improved by cross checking that the best flight plan has been selected with a central office. Centralizing this function would facilitate adherence to standards set by the airline.
For passenger/crew comfort and reduced wear I would say large deviations are a no brainer given the relatively low cost.

SaturnV

10th Jul 2009, 17:20

DutchBru, Dispatch was not asleep.

At 0 h 31 dispatch sent the following message:
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,

The BEA report notes that AF447 did not request copies of any SIGMETs through ACARS, ... "that functionality was not used by the crew."

Cloud tops at -60C about 0200 June 1

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0329-1.jpg

Tops at -70C

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0328-1.jpg

Tops at -75C

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0327-1.jpg

While I have seen the information on experience and hours on type, etc., I've not seen any information on how many times the three pilots have flown on this route. Has anyone?

AstraMike

10th Jul 2009, 17:26

Some questions:
1. Would the A330’s engines continue to run in the event of a Flat Spin, considering the intake angle to relative wind would be upwards of 60° and as much as 90°? Even though Relative Wind in severe convective activity with tops in excess of 50,000 feet, with potential for both vertical and horizontal air currents, may be a little hard to define… I would suggest that although the potential of ice may be a contributing factor, it is not required to lose the engines.
2. If the engines did fail, would the ACARS system still have the power necessary to transmit and receive and would data still be available for download to the ACARS system? I suspect not.
3. Given the size and condition of some of the recovered bits and pieces, with particular reference to the Galley, what logical solution is there apart from the Flat Spin that will bring the aircraft from where it was, to where it ended up, with just the right momentum to break its back, yet not destroy its contents beyond what we see? I suspect that in practical terms there is none.
4. Does tracking the transmitted 10 minute position reports and the last position transmitted take the aircraft through the convective activity displayed on the satellite graphics as submitted by Tim Vazquez, as it appears it does, and if so, what activity would you expect within such weather, especially as it seems to have been building at the time? Moderate or Extreme turbulence? Vertical air currents? Horizontal air currents? I would suggest all of the above
5. I understand, from reading this thread, that AF447 likely had limited rudder authority. Can it then be assumed that there was no rudder, or not enough rudder, to keep the wings level during the flight complexity of CB penetration, especially considering the effects of adverse yaw, should aileron be used at unintentionally high angles of attack? In other words is limited rudder authority, necessary in cruise, a detriment that might even contribute to an accident in this case?
6. Is it reasonable to suppose that given entry into the convective activity, apparently present in the area, as would appear likely to most, the crew would be faced with an impossible situation with an aircraft dancing around at the mercy of the storm (for want of a better description) small room for error with VS on one hand, VD on the other and apparent loss of rather important information (airspeed)? Not that it would make that much difference as it would likely be impossible to read the tape anyway, nor is it too likely that they could keep the aircraft level either in pitch or roll as nature played with it; you just cannot underestimate the power unleashed in these things and you simply cannot predict what will happen next.
7. Which pilot, hand on heart, would ever think of turning in a CB, let alone turning back to go through it again once it has caused difficulty? Nobody I know!!
8. Why is it so difficult to believe that loss of control due to weather assisted by pitot ice resulting in a spin is the most likely outcome?
9. You can be fairly certain that a Flat Spin does not degrade into a “full” Steep Spin, or a Spiral Dive, which might be considered a part of a recovery (getting the nose down) – if you are fortunate enough to do so, which is doubtful unless the weather that got you there also influences a recovery assist. With the wrong (or right, depending on your point of view) control inputs a Steep Spin will turn into a Flat Spin, even without the effect of turbulence which is quite likely to do the job for you.
10. I say again, do not underestimate the forces at work in a building 50,000+ foot convective build-up, I am sure most pilots respect and avoid them, so to suggest a crew, any crew, would turn back into the weather is frankly unbelievable – in fact even attempting a turn in the condition one can suspect they had on their hands would be frankly foolhardy and does not allow the crew the credit they deserve.
11. Although subject to considerable yaw force, it should not be assumed that a flat spin will cause the Vertical Stabilizer to part company, (it might actually be blanked out by the wing) or that such a departure is required to establish a flat spin which has a rotational rate that is less than a Full Spin and a rate of descent that is also about 50% less than a Full Spin all of which makes it the more logical manoeuvre for getting from A to B given the apparent arrival impact. I suspect it is far more likely that the Vertical Stabilizer failed as a result of the forces in play at impact, but would not insist on it.
12. Center of Gravity in a flat spin will really only dictate the relative position of the nose to the horizon – which need not be constant initially. It is easier to Flat Spin an aircraft with an aft (less stable) C of G and if cruise policy is to operate this way, it only adds to the Flat Spin suspicion. An aircraft with a more forward C of G will simply not look as flat.
13. I asked before if anyone could recognize a spin on instruments – no one seems to have that confidence. When I was in a Flat Spin I was VFR and could see the horizon going round, and round and round. I wonder how electronic instruments would depict this, would they become non-functional as the old steam driven instruments did. I don’t expect you could tell what was going on unless you had been there before, in the not too distant past
14. What was the sea state at impact? Anything but smooth, I suspect, yet the talk is as if the aircraft arrived out of the overcast in a glide, or at worst in a spiral and didn’t quite manage to pull out. This sort of thing typically ends up with what was an aircraft wrapped into a ball of wreckage by the forces of impact and sinking in tiny pieces. The dead stick landing in the river recently was impressive because of the unusually minimal damage caused. All the indications we have seem to refute this sort of scenario. But the sea and changing winds under the convective skies must surely have played a part that “normal” can't explain.
15. I have never flown trans-oceanic without guarding (listening to) 121.5. In fact I seldom fly anywhere without having it quietly selected. Other aircraft in the sky that night were doing just that – of course they were, they were diverting off course and announcing their intentions, as a courtesy, no doubt – yet none heard a word from AF447, no courtesy advice of a diversion, no mayday, nothing. That, and the fact that life vests do not seem to have been deployed, or should I say the cabin prepared, implies sudden onset of something totally unexpected that, simply took over.

In the end, it doesn’t really matter how the aircraft descended. I think one of the few things agreed is that it did, and no one can turn back the clock; it’s all history now. What matters is; what happened to cause the series of events that defeated the aircraft and its crew? There are not that many candidates and I would suggest pitot ice alone would not be one. From many of the things stated on this thread, there would appear to be some dark corners in airliner cockpits where light needs to shine and lessons be learned, other than the more obvious avoidance of weather.

L337

10th Jul 2009, 17:27

Anyone know what the major airline policies/guidance are for deviation due to weather?

From my FCOM: Monitor the weather at both long and short ranges in order to plan efficient
course changes. When avoiding storm activity stay upwind of the storm, if
possible. If thunderstorms exist over the landing airfield or landing reports
indicate severe turbulence, consider delaying landing or diverting.
Plan ahead to avoid large storms:
Avoid magenta and red radar returns and fringes by at least 20 nm.
Avoid single magenta areas of turbulence (not associated with heavy
precipitation) by at least 5 nm.
Avoid penetrating a cell or clear it’s top by less than 5000 ft, otherwise
severe turbulence may be encountered.
Do not overfly cells if the top of the cell is at or above 25000 ft to avoid
the possibility of encountering turbulence stronger than expected.
Avoid flying under a thunderstorm due to possible windshear, microbursts,
severe turbulence or hail.
If severe turbulence cannot be avoided, an increased buffet margin is
recommended. This can be achieved by descending up to 4,000 ft below
the FMS optimum altitude.
Adjust the tilt frequently in order to monitor storm development and to get
the best cell echo.

Curiously a LH flight and another AF flight the captains chose to try to pick a hole through the weather system.

I assume as they must still be alive, they did not "try to" they did pick a hole.

Is it a question of the captain filing a flight plan and it is never reviewed or questioned?

It does not happen like that. A large computer talks to another large computer and extracts all the weather, the winds, notices, navigation charges, fuel Price, and a hundred other items, and it produces an optimum route for the flight. The company file the flight plan. The controlling item is almost always cost. Having received all the paperwork for the flight I and the crew then review it all. If I think we need more fuel for the route, that is my decision. So if I see some nasty weather on my route that might cost me extra fuel, and I want to take extra fuel, I do. If I want another route, I phone the office up and ask for one. As Captain the buck stops with me.

For passenger/crew comfort and reduced wear I would say large deviations are a no brainer given the relatively low cost.

The 747-400 burns roughly 10,000kg of fuel an hour. It all adds up.

Safe and Commercial is the plan. Safety comes first always, but it needs to be commercial as well. After all the safest thing is just to stay in bed...

Mudman

10th Jul 2009, 17:32

If the engines flamed out as some folks have theorized would no electrical power from the engines mean that the FDR and CVR would stop working? Is there an alternate power source for them? I think this happened on Swiss Air 111, Eygpt Air 990 and American 587, the recorders stopped before impact.

thanks.

(if this is irrelevant or redundant please delete)

All-Ex

10th Jul 2009, 17:41

SaturnV: While I have seen the information on experience and hours on type, etc., I've not seen any information on how many times the three pilots have flown on this route. Has anyone?From the BEA interim report page 12ff:
Captain:
The captain had carried out sixteen rotations in the South America sector since he arrived in the A330/A340 division in 2007.

Co-Pilot 1:
This pilot had performed 39 rotations on the South America sector since arriving in the A330/A340 division in 2002.

Co-Pilot 2:
This pilot had performed five rotations in the South America sector since arriving in the A330/A340 division in 2008, including one to Rio de Janeiro.

LeandroSecundo

10th Jul 2009, 17:47

Hi,

Some answer about deviation (supposed) there

AF 447 : comme Lufthansa, l'avion a dévié à l'Ouest de sa route prévue

Eurocockpit - Accueil (http://www.eurocockpit.com/index.php)

Bye.

Razoray

10th Jul 2009, 18:07

Mudman.....

On Swiss Air 111 the FDR stopped working because the cockpit burned up...

spagiola

10th Jul 2009, 18:51

Some answer about deviation (supposed) there

AF447 : comme Lufthansa, l'avion a dévié à l'Ouest de sa route prévue (http://www.eurocockpit.com/index.php)

A quick summary of what eurocockpit is claiming, for non-French readers:

The last reported position of AF447, at 0210Z, is actually about 3nm west of track, so it is likely that AF447 was in fact deviating to avoid weather. Given GPS etc, this discrepancy is unlikely to be due to poor navigation; nor is it an offset, as that would have placed AF447 1 nm EAST of track.

Thus they place in doubt BEA's finding that AF447 was on track, and AF CEO Gourgeon's suggestions that perhaps the crew of AF447 didn't use their wx radar appropriately.

(Before someone asks, I grew up in France and the French-speaking part of Switzerland, and I'm a pilot (albeit only PPL) and so understand aeronautical French as well as normal French)

wilyflier

10th Jul 2009, 19:01

Flat attitude
A lot of time with semantics was spent on the exact attitude
"en ligne d`vol ",flat horizontal,with very little forward speed...
With regard to the VS possibly being ripped off to tumble forward.
How stormy was it at sea level? How big the swells?
I envisage a tail down approach (not into wind, cross swell), at high attitude and hitting the back face of a swell smack on, sufficiently to break the belly in.
(Think 737 on the Motorway embankment at Derby)
With for good measure the tail cone clipping a previous swell and breaking UP
Thus striking and crushing the rudder base and catapulting it forward free of its compromised hull structure
This explains the ability of the hull to hit the water surface forcefully wth mainly 90 degree impact while still having a much more credible forward airspeed.
Of course it would stop in the water very quickly with the following swell "pooping" and washing out the now opened hull, and smashing into the back of the vulnerable spoiler(s)

takata

10th Jul 2009, 19:45

FanAviation:
...So the conclusion is neither the captain nor co-pilot1 ever flew to Rio. Only co-pilot2 flew there once...
I noticed that when I read the report but not being a pilot I don't know how important to the crash it could be, or not...
Hi,
May I ask you where did you read that in the report and to quote it for my better understanding, please?
(Is it that hard to verify such a claim presented as the conclusion before posting it?)

S~
Olivier

Porker1

10th Jul 2009, 19:49

Blimey Wilyflier - given the paucity of the information I can only say that you have a heck of an imagination!

FanAviation

10th Jul 2009, 20:07

Hi Takata, I presume your question is about "my" conclusion and not about the facts (as you already said that the experience of the pilots was in the report...) So...
I am french (so are you as I strongly suppose...) and to a frenchman the fact they say : captain 16 rotations to SA, co-pilot1 39 rotations to SA, co-pilot2 5 rotations including 1 to Rio is the obvious (to me!) proof the others have not. Else why would they specify this fact ONLY for co-pilot2?

WilyB

10th Jul 2009, 20:36

Else why would they specify this fact ONLY for co-pilot2?

Maybe because with only five rotations, there might have been a slight chance he never few that route?

Remember: always go for the simplest explanation. :)

spagiola

10th Jul 2009, 20:50

Does it really matter how many times they might have flown this specific route? As we know from AF559, the route from Sao Paulo is practically identical to that AF447 followed, and any other route from the Southern cone would have crossed the ITCZ in the same general area, if not on the same path.

Razoray

10th Jul 2009, 20:50

takata & WilyB

I think it is obvious by the report that the Captain had plenty of experience. That is not the issue. The issue is that no one knows for sure where he was when the proverbial sh*#t hit the fan!

Apparently he may have been sleeping......

:zzz:

xcitation

10th Jul 2009, 20:56

Thanks for the detailed response :ok: L337 (http://www.pprune.org/members/32539-l337) .

Given that all the other flights had to alter their course to avoid the weather then I think it is safe to assume that AF447 would have had to do the same thing at some point.
What is odd that from the limited data we have it appears that AF447 made no manouvering upto the point of the incident. This is remarkable given the path of the a/c when overlayed on the various satellite images.

Data points:
no pre-flight extra fuel
no known voice comms of course/altitude alterations
no known requests for extra optional weather info
no course alterations when entering the immediate vacinity of the CB cluster

Could weather avoidance manouvers have omitted for some reason and if so why?
Clearly the pitot's iced and it quickly went from bad to far worse. Other flights had experienced the pitot problem and delicately flown via N1 and attitude until the pitots cleared. Clearly there is still a piece(s) missing, a nasty updraft / losing a control surface due to inaccurate IAS / or something else to upset the a/c whilst flying with limited instruments in ALT LAW. Whatever it was it happened extremely fast to prevent any "we're down" message from the crew or from passengers via satellite phone.

Having read that the US are giving up the search, I hope that the French g'ment does whatever it takes to recover the FDR/CVR. If we can find the Titanic then we can find F-GZCP. Just because the pingers have failed the data is still there in all liklihood.

We do not want a repeat of this incident. The French g'ment needs to consider that if a similar incident happens in 12 months then they could regret not having done more this time around especially if it turns out to be an easily corrected fault.

LeandroSecundo

10th Jul 2009, 21:14

Hi,

Given that all the other flights had to alter their course to avoid the weather then I think it is safe to assume that AF447 would have had to do the same thing at some point.
What is odd that from the limited data we have it appears that AF447 made no manouvering upto the point of the incident. This is remarkable given the path of the a/c when overlayed on the various satellite images.

Read this when available in english (soon)

Eurocockpit - Accueil (http://www.eurocockpit.com/index.php)

Bye.

Will Fraser

10th Jul 2009, 21:40

This a/c did not have a 'three pilot crew'. It had two pilots and a relief pilot. Where the Captain was, if not on the FD is irrelevant, he was not PIC at the time two other qualified pilots were in the two (provided) seats. Further, my understanding is that the F/O would be PIC and flying from his (right) seat. Is that it? Because if Captain is allowed to leave the FD and catch some sleep, isn't it understood he may be unavailable, and by design? F/O also has most time in type, 4700 hours? Is this pilot thing really an issue?

edit: F/O (copilot 1) time in type/ correction 4,479 hours

PJ2

10th Jul 2009, 21:47

L337;
Safety comes first always, but it needs to be commercial as well
Succinct and absolutely correct post. Well done.

My point on this need has always been, commercial viability but with safety paramount, (and pilots realize this far better than the beancounters).

It has to work commercially. The "insurance policies" for doing this safely are:

a) highly-trained and motivated workforce,

b) leadership by, support of and defence by the CEO for expenditures on "non-profit-making" safety programs, (I know an airline that termed the Safety Department a "Profit Center" for god's sake, solely in keeping with an MBA's view of the corporate bureaucratic world) and

c) a willingness to continously examine and accept the nasty bits of aviation so they don't bite one in the ethical, corporate and legal ass, and finally,

d) an abiding, clear and firm intolerance straight from the top of the organization, for departmental trading off of commercial priorities with safety priorities. I've seen that occur and accepted as far up as the CEO; it is dangerous work when that occurs.

In other words, if the organization is concerned for it's profitability and he leadership broadcasts to employees that "cost" as the organization's biggest concern and, because survival in the bureaucracy works that way, that is precisely what department heads will begin to tell their subordinates and what they will extract from their people. Nobody wants to look bad at meetings or in the numbers. The CEO is the person to ensure that that doesn't happen.

Mudman;
If the engines flamed out as some folks have theorized would no electrical power from the engines mean that the FDR and CVR would stop working? Is there an alternate power source for them?
Correct; the FDR/CVR would stop working should the AC1 or AC2 buses lose power. It is presently an issue within the safety and regulatory community. Swissair's recorders were lost at about 6000ft due to the rapid degradation of the electrical system, most of the relays, computers and controls for which were located in the cockpit and under/cockpit area. Control of the aircraft is assumed to have been lost at that point.

Razoray

10th Jul 2009, 21:48

Will Fraser

Point Taken......

xcitation

10th Jul 2009, 23:24

Quote:
Some answer about deviation (supposed) there

AF447 : comme Lufthansa, l'avion a dévié à l'Ouest de sa route prévue (http://www.eurocockpit.com/index.php)

A quick summary of what eurocockpit is claiming, for non-French readers:

The last reported position of AF447, at 0210Z, is actually about 3nm west of track, so it is likely that AF447 was in fact deviating to avoid weather. Given GPS etc, this discrepancy is unlikely to be due to poor navigation; nor is it an offset, as that would have placed AF447 1 nm EAST of track.

Thus they place in doubt BEA's finding that AF447 was on track, and AF CEO Gourgeon's suggestions that perhaps the crew of AF447 didn't use their wx radar appropriately.

(Before someone asks, I grew up in France and the French-speaking part of Switzerland, and I'm a pilot (albeit only PPL) and so understand aeronautical French as well as normal French)

Was F-GZCP significantly off course at the actual time of the faults (as opposed the ACARS time stamp)?
If the answer is yes then that has implications. Why was ATC/nearby a/c not notified of the course change. Obviously in an emergency flying comes first so one hypothesis would be that an emergency had already occurred prior to pitots failing.
The BEA interim report does not mention this explicitly (if it does please give page.) I did find this:
(p.68 english copy)
up to the last automatic position point, received at 2 h 10 min 35 s, the flight had followed the route indicated in the flight plan,
Coincidently 0210Z was the time that ACARS alerts appeared and the controls reverted to ALTN LAW there was a GPS position reference. There is some latency which delays the maintenance reports.

lomapaseo

10th Jul 2009, 23:24

Just a couple of data points for the "what if" folks here.

Engines rarely flame-out completely but may rundown and have to be restarted. It's therfore not likley that the generators are going to be tripped off-line for all engines at the same time.

In aircraft upsets the engines often stall due to shearing of the air across the inlet. Often confirmed at low altitude as bangs and flashes of flame. I don't recall any data of such at altitude.

In most upsets at altitude wing mounted engines get slung off the wings if high yaw rates are involved. PA103, TWA800 AA587 etc.

Robin42

10th Jul 2009, 23:38

RIO - The number of identified victims of the Air France flight 447 suffered this new amendment Tuesday.
Representatives of the Federal Police, Office of Legal Medicine (IML) and Secretariat of Social Defense (SDS), which joined the Task Force responsible for the identification of victims of air disaster, said that an examination of DNA showed that a fragment a of body that was found at sea belonged to a body that had been collected. With this identification, the number of found victims reduced from 51 to 50.

Of these, 43 have been identified. Seven bodies in the IML still await identification, among them, the body which the fragment belonged.

According to the head of Forensic Science, Francisco Sarmento, all the bodies had multiple fractures and injuries, probably caused by the impact, which was the cause of death.

- The victims had multiple fractures, injuries and ruptures of internal organs, evidenced by impact.

- The information I can give is that the the death was caused by impact, which is characterized by the presence of polytraumatic injuries, he said. Source: A somewhat corrected output of a Google translation of Cai de 51 para 50 número de vítimas do voo AF 447 - O Globo (http://oglobo.globo.com/mundo/mat/2009/07/07/cai-de-51-para-50-numero-de-vitimas-do-voo-af-447-756690545.asp)

So it appears a bit more likely now, that the plane came down in one piece -- not because of the impact itself, but for the cruel detail which also allowed to reduce the number of victims from 51 to 50.

ArthurBorges

10th Jul 2009, 23:49

I hope that the French g'ment does whatever it takes to recover the FDR/CVR.

The last I read, the French attack submarine Emeraude was to search until July 10; after that unmanned minisubmarines will continue looking for whatever is left of the aircraft.

Will Fraser

10th Jul 2009, 23:57

LeandroSecundo

11th Jul 2009, 00:29

Hi,

I did find this:
(p.68 english copy)
up to the last automatic position point, received at 2 h 10 min 35 s, the flight had followed the route indicated in the flight plan,
Coincidently 0210Z was the time that ACARS alerts appeared and the controls reverted to ALTN LAW there was a GPS position reference. There is some latency which delays the maintenance reports.In waiting a translation from the original .. this is a Google translation of a extract:

For example, page 48 of the BEA report, it shows "the last position received" of 2.98 ° (2 ° 58.8 ') north and 30.59 ° (30 ° 35.4') west to 2:10 UTC.

On a map, it can easily be carried as part of the "route to the flight plan" between "ORARO and TASIL.

Between these two points, the course "right card (straight between two points on the card) is similar to circle route (corresponding to the curved line between those two points on the earth sphere). Indeed, the distance between these two points is only 119 Nm and the "arrow" (lateral deviation between the right map, and circle) is negligible over such a short distance.

The report of the position of flight AF 447 to 2:10, with the coordinates provided by the BEA, place the aircraft at about 2.9 nm west of the road.

For the curious, an official Jeppesen electronic road can be checked easily graphically.

A calculation of spherical trigonometry mathematical and precise, we wish to provide for some having doubts, gives a gap approached 2.9439071 Nm The maximum error of the accuracy of the values of position given by the BEA is 0.5 tenths degree, in one way or the other.

In other words: at 2:10, Flight AF 447 is not on the planned route in the flight plan ", as the BEA, but almost 3 Nm to the west of it.http://www.eurocockpit.com/images/UN873.jpg

http://www.eurocockpit.com/images/UN873Z.jpg

Bye.

Will Fraser

11th Jul 2009, 00:34

447

0135 established, stable cruise, M.82 FL350

0210 a/p auto disconnect, to include A/THR and ALT LAW 2

0214 last ACARS, last anything.

UNK Entered the Sea per description by BEA

Hypotheticals:

Prior to a/p disc. the pilots noted turbulence. If so, they made a decision to allow the a/p to continue. In this case, they would have been prepared for 'handback'. If they either didn't notice turbulence, or there was none, the a/p disconnected 'suddenly' with a sudden onset of a/c response that was above programmed limits. In other words, the decision was likely made to allow the a/p to continue to fly. It would take a series of coincidences to have occurred (faults) that were simultaneous with a/p disconnect; if not, then a/p disconnect was a result of something that happened prior, e.g. pitot problems.

With Unreliable a/s, my assumption would be that Pitch would be the instantly necessary mitigation (probably to lower the nose if IAS was 'low'.) If the a/p lowered the nose to its limit then dropped out, wouldn't the 'sudden loss' of autoflight call for some time lapse for pilots to get up to 'speed'? Also, without a/p and a nose trending down, (what's to arrest the Nose Down momentum?) could the Nose be quite low, speed building rapidly, and the a/s still indicating 'low'? Overspeed alerts, low IAS, loud slipstream, a handful of other demanding issues, etc. etc.

What would AB Alt Law 2 be doing at this point relative to recovering, especially the controls, arresting overspeed, etc. What is the pilot's expectation of the a/c's behaviour, given that his own SA is limited?

edit. : LeandroSecundo In your translation it is said "the distance is only 119 nm. and the arrow is negligible over such a short distance". Wouldn't any course deviation be enhanced as distance shortens? Isn't three nm 3 degrees in 119 nm? edit. that isn't 'on course'.

grizzled

11th Jul 2009, 01:14

Will

Re your comment about the 3nm displacement.

LS is, I think, not referring to the actual a/c position but to the relationship between a "straight line" on a chart, over a short distance, and the actual shortest distance (i.e. derived from a great circle or the distance as per spherical geometry). The shorter the distance the less lateral deviation between the two. The greater the distance, the greater the lateral deviation.

So it seems you are both saying the same thing: A 3nm lateral displacement over that distance (119 nm) is much more than can be accounted for by citing the differences between navigating and/or plotting positions using a straight line on a chart, or a formula that allows for navigating over a sphere (as per WGS84, GPS software, etc).

lomapaseo

11th Jul 2009, 02:31

Other than 'slung off', how would an engineering discussion characterize the analysis of 'failure' (engine loss from mountings) ? That is to say, there is probably a difference between 'yaw angle' and 'yaw rate' ?

Well the angle part only implies an aero drag load while the rate part implies inertia loading. I crudely used the term yaw since in an aeronautical sense most folks on this forum relate. However even if the plane is not moving along its horriz axis a flat spin component will do the same trick.

JD-EE

11th Jul 2009, 02:31

LonardoSecundo,

May I suggest an addition to your remarks here. You must consider the accuracy of the report and the precision of the report. You add them to get the maximum error band. The precision is how many decimal places are presented. The accuracy is related to the accuracy of the data before transmission.

The precision of the raw data is two decimal places, 1/100 of a degree. This is shown on page 46 of the English report and is not shown on the corresponding list on page 49 of the French report. 1/100 of a degree is on the order of 0.6 nautical miles.

The English language report simply declares, "The position transmitted was the aircraft’s FM position which, in normal conditions, is close to the GPS position."

You stated, "The maximum error of the accuracy of the values of position given by the BEA is 0.5 tenths degree, in one way or the other."

That would be on the order of 5 times the 1/100th degree report precision or about 3 nautical miles. Adding the two, which is conservative since we do not know if the position was truncated or rounded in one direction or the other, we get about 3.6 nautical miles. That places the plane on its proper line of flight within the total accuracy we can expect.

Supposing you misstated what you meant the results are different. The accuracy before rounding of the FM position may be close to the 1/1000th of a second GPS reports or even the 100 meters or more the plane FM rounding would not materially degrade the precision of the report. That would mean they're about 2.3 nautical miles left of track. They may have started a turn a few seconds before the report. Or they may have already been in trouble of some sort.

JD-EE

LeandroSecundo

11th Jul 2009, 04:06

Hi,

You stated, "The maximum error of the accuracy of the values of position given by the BEA is 0.5 tenths degree, in one way or the other."I stated nothing .. I just quoting this site :) and Google translation.

Eurocockpit - Accueil (http://www.eurocockpit.com/index.php)

BTW.. this link was already in my first message about this analyse.
And it's indication as a english version will be available soon.

Bye.

blueriver

11th Jul 2009, 04:24

Will Fraser wrote:
Prior to a/p disc. the pilots noted turbulence.Will,

Apologies if I'm wrong, but I thought the pilots reporting turbulence was misreporting in the media and they actually never reported turbulence ??

Will Fraser

11th Jul 2009, 04:30

blueriver

The two pilots noted turbulence in real time, not as a tx. Not that they 'reported' it, they made note of it to eachother, or FP communicated it to PNF. Read what follows, these are 'possibilities'.

blueriver

11th Jul 2009, 04:37

Will Fraser wrote:
The two pilots noted turbulence in real time, not as a tx. Not that they 'reported' it, they made note of it to eachother, or FP communicated it to PNF.

Thanks for clearing that up for me. I missed that bit.

PickyPerkins

11th Jul 2009, 05:10

#3452 stated:
Data points: no pre-flight extra fuel

This may not be quite right, because the report says on P. 19:
"The on-board fuel weight corresponded to forecast trip fuel of 63,900 kg,
route factor fuel of 1,460 kg,
final reserve of 2,200 kg,
fuel to alternate airport reserve of 1,900 kg and
940 kg additional fuel.
An LMC (last minute change) corrected the definitive load sheet to take into account one passenger fewer without baggage."

So, it had 940 kg additional fuel.

Also, the report says on p. 18:
"The estimated takeoff weight was 232,757 kg (11),
for a maximum authorised takeoff weight of 233 t."

So, the a/c was 243 kg under MTOW on take-off, about 0.4% of the total fuel load, with not much of an option to take on more fuel.

The report also says it left the gate over MTOW.

Without the LMC, the TO weight would have been even nearer the MTOW, 91 kg nearer if the missing passenger was a man, 72 kg nearer if a woman.

Looking at the fuel planning, it looks as though the Captain thought it was likely that he might have to deviate for weather. http://pickyperkins.home.infionline.net/pi.gif

JD-EE

11th Jul 2009, 05:34

I did indeed err in the attribution. Please accept my apology.

Here is a link to the full article that is more permanent than the one you showed. Eurocockpit - Archives (http://www.eurocockpit.com/archives/indiv/E009465.php)

It appears the original French indicated "0,5 dixièmes de degré" which surely looks like an awkward way of saying 0.05 degrees or 3 minutes of angle. The plane appears to be well within that error band.

JD-EE

threemiles

11th Jul 2009, 06:20

The English language report simply declares, "The position transmitted was the aircraft’s FM position which, in normal conditions, is close to the GPS position."
FM = FMC ?
This implies that ACARS uses the GPS position as a source and not the IRS which may be a few dots off the real position after the loss of nav updates.

SALPU and ORARO position reports
I have found nowhere that these position report were obviously missed. I cannot find that Atlantico said "next report TASIL". SALPU and ORARO arecompulsory reporting points and should have been reported by the crew outside radar coverage. Estimated crossing times from the INTOL report (0133) would have been SALPU at 0148 and ORARO at 0200.
Also Atlantico should have been after these report within a few minutes after they were failed to be reported. It was obviously not.

Though it may be bothering to report every 12 to 15 minutes in a comms hostile environment and with the possible difficulties to get in contact to Atlantico on HF (not seen this in the report, just the inability of other planes to get a response from Dakar which may be due to other reasons as those of us can imagine who fly there) the crew would have normally tried to relay the report though other aircraft on 121.5. Or?

All this sounds theoretical as there seems to be an accepted lack of discipline about comms and reporting in this part of the Atlantic. I would see this as a contributing factor to the delay of the rescue missions.

A compulsory report is what it says. It is absolutely necessary that ground stations can expect that reporting duties are taken serious and a missing report signals something critical. It is then necessary that ground stations become alert immediately if a report is missing and an alert distress phase is initiated.

Even if the relict of propeller flying, which HF is, is not working there are other means to get a report passed on to the controlling center as Iridium phones or SATCOM ACARS to homebase operator and then by phone or SITA through landlines.

The reliance on "modern"technologies as ADS-C and then give up to report as they may not work is not adequate. However ADS-C in this case was present for the Dakar FIR only, not the Atlantico FIR.

I could not imagine that neither airside nor landside behaviour would have happened inside Gander or Shanwick airspace.

Squawk_ident

11th Jul 2009, 08:03

From Xcitation

Having read that the US are giving up the search, I hope that the French g'ment does whatever it takes to recover the FDR/CVR. If we can find the Titanic then we can find F-GZCP. Just because the pingers have failed the data is still there in all liklihood.

About the signal from the BB. I've heard on the 02nd just after the press conference from a journalist that hat attended to it that, from the 14th of Juy new method(s) should be deployed to find the boxes and that the searches would be stopped whatever are the results on the 15th of August.
I haven't heard something new since.

Threemiles

SALPU and ORARO position reports
I have found nowhere that these position report were obviously missed. I cannot find that Atlantico said "next report TASIL". SALPU and ORARO arecompulsory reporting points and should have been reported by the crew outside radar coverage. Estimated crossing times from the INTOL report (0133) would have been SALPU at 0148 and ORARO at 0200.
Also Atlantico should have been after these report within a few minutes after they were failed to be reported. It was obviously not.

ORARO estimate was a discussion that I had a while ago with mm43.
I now think that ORARO estimated at 0200 could not be correct at 0.82 and that it was 0204 as shown by the radar traces and Acars messages. May be that the crew has misread an entry in the CDU.
Because the estimate TASIL was not received by Atlantico, it was very likely calculated by them according to what they could see ont their radar at INTOL and (almost) SALPU. I agree that SALPU and ORARO being compulsory, Atlantico should have (Sel)call AFR447 to confirm the position and request also TASIL again. Like mm43, I think that they did not mind because the traffic on this route was not important and, also perhaps because of their working load. I think that controller(s) are making at the same time VHF and HF COM and that time was lacking for them to properly handle all communications with a given traffic. Or may be a poor communication between different ATC sectors.
Assuming that on this route it was not unusual to be unable to establish contact with traffics, they did not get alarmed. Some pilots used to these routes might enlighten us on this.

WhyIsThereAir

11th Jul 2009, 10:00

In other words: at 2:10, Flight AF 447 is not on the planned route in the flight plan ", as the BEA, but almost 3 Nm to the west of it.

Does anyone know if eurocockpit (or anyone else) has done this same analysis on the other waypoints reported? Unless they can show that all other points are exactly on the flightplan line this final deviation may not be what they are claiming.

Question for pilots; I apologise in advance for not knowing this: when you set the AP to go from ORARO to TASIL, do you key in "TASIL" and the AP knows where it is, or do you dial in the coodinates of TASIL from the flightplan or memory?

hetfield

11th Jul 2009, 10:34

High crash rate for Airbus Air France

Secret calculations aviation circles reveal a devastating result for Air France: Airbus to the French airline crash often from above. An internal report to the SPIEGEL exists, criticized poor safety culture of the company.Google Translation of todays SPIEGEL

Interner Bericht: Hohe Absturzquote bei Airbussen von Air France - SPIEGEL ONLINE - Nachrichten - Wirtschaft (http://www.spiegel.de/wirtschaft/0,1518,635583,00.html)

:hmm:

Robin42

11th Jul 2009, 11:24

Does anyone know if eurocockpit (or anyone else) has done this same analysis on the other waypoints reported? Unless they can show that all other points are exactly on the flightplan line this final deviation may not be what they are claiming

The problem is, that the exact values of the other waypoints aren't known to the public until now. But Page 13 of the French version of the BEA report has a Google Maps image of the flightpath, also showing the ACARS waypoints. Zooming up that map and assuming these waypoints had been entered using the same precision, I'd think they line up very well, except for the last one, which is slightly deviating to the West.

WhyIsThereAir

11th Jul 2009, 12:19

Eurocockpit claims that "AF447 was 3 Nautical miles west, well en route for a 10-nm deviation to avoid wx"... So? What do you think?

I don't know that there is enough information publically available to make thinking possible. Simply going by the route map in the report, yes, there does seem to be some deviation in the 02:10 location. I'll believe that it might have been 3nm off the centerline of the track.

However, the "well en route for a 10-nm deviation" seems to be unsupportable, because we have no idea when they begain a turn, we do not know if they are still in the middle of a turn, and of course we don't know (but can perhaps guess) a turn rate.

LeandroSecundo

11th Jul 2009, 12:37

Hi,

English translation available here:
Eurocockpit - Archives (http://www.eurocockpit.com/archives/indiv/E009465.php)

Bye.

Robin42

11th Jul 2009, 13:09

JuggleDan,

well, it's probably only a subtle pitfall prepared for non-native speakers, but, considering the positional messages are actually spaced at 10 min intervals, does the notions "up to the last automatic position report" or "jusque'au dernier point de position automatique" actually includes the last position?

jusqu’au dernier point de position automatique, reçu à 2 h 10 min 34, le vol s’est déroulé sur la route prévue dans le plan de vol,

up to the last automatic position point, received at 2 h 10 min 35 s, the flight had followed the route indicated in the flight plan,

I consider also the following points:

- The F/O had even more experience than the captain on type: 4479 vs. 1747 flight hours, and a well comparable overall experience.
- The F/O had even more experience than the captain re South American destinations (39 vs 16 rotations)
- GPS precision with 12 satellites in sight is around 4 m on the ground.
- ACARS messages reporting GPS failures or severe degradations had not been transmitted

JuggleDan

11th Jul 2009, 13:48

WhyIsThereAir, Robin42,

First of all, thanks for your answers.

The way I see it:
- In technical French, when you speak about a line segment, you can either say "jusqu'à ce point inclus" (end-point included) or "jusqu'à ce point exclus" (end-point excluded).
- If you don't give any further precision, as it is the case here, it most often means that the end-point is included
- Thus, I certainly understand the BEA report as saying that all position reports were sent from the a/c nominal route, up to and including the last message at 0210 .

surplus1

11th Jul 2009, 13:52

Why is it important if the a/c was 2.5 or 3 m west of track or directly on track? What difference would that make re the outcome?

Whether it was on track or 10, 20, or even 50 miles either side of track, whatever happened did so regarless of its precise position. Since we do not know the pricise position of any convective activity that may have been present in the area, or if that was a factor in this accident, the exact position is not relevant.

If a ship hits an iceberg in the ocean it doesn't matter whether it hit it on course or off course. The only thing that matters is what happened to the ship after the impact.

This was open ocean. There is no terrain for the aircraft to fly into by being somewhat off course. The information is irrelevant to the cause.

So is all the detailed information with respect to ocean currents and locations of debris. They may be very useful in locating the point of impact and therefore narrowing the search for the recorders or the remains of the aircraft, but in and of themselves they are not useful in determining the cause of the accident.

Dutch Bru

11th Jul 2009, 14:29

Flight crews avail themselves of ACARS met reports all the time. In my experience, company dispatch provided timely and up-to-date information on SIGMETS as a matter of flight following, a legal and operational requirement in many states. Most crews would plot the SIGMET'd area on their planning charts then keep a wary eye using all available techniques including radar. That is not where the problem lies. The problem is in teaching how to use the radar "optimally". Likely, most pilots pick up the use of their radar through "osmosis", which does not filter misunderstandings and shortcomings in knowing one's equipment.

Thanks, PJ, but the smart use of wx radar starts with being aware that things are tricky and warrant extra vigilance. My point is that since the AF447 flight crew according to the BEA report did not ask for nor did they receive SIGMET updates by ACARS, they were disadvantaged in their awareness. And I agree with you that SIGMET and other weather related info is and should be regularly supplied through ACARS, certainly on long distance flights. This makes the BEA statement on the absence of such communication with AF447 even more significant.

Saturn V, where did you find the ops message on the weather (your post 3437)? Surely not AF447 related; I stand to be corrected, but I couldn't find that in the BEA report (as there is no mention of SIGMET 8 and 9 for ATLANTICO FIR)

ArthurBorges

11th Jul 2009, 14:39

I'd started my own translation in a vain bid to beat Eurocockpit, if for little real reason other than idleness and a personal interest in AF, so here it comes -- if this has a stronger dose of sarcastic spin, I stand by it (once checked draft):

AF 447 Deviated West Just Like LH507

Page 71 of the BEA report lists the so-called "first established facts". Their order of presentation is semantically deliberate: words assume fullest meaning when in the right order. True, BEA did have a whole month to think things through.

Here's the demonstration:

"Up until its last automatically-reported position, received at 021034UTC, the flight was proceeding on the route given in the flight plan."

IN CLEARSPEAK: AF447 made no deviations.

"Weather conditions were consistent with what is normal in the intertropical convergence zone in June."

IN CLEARSPEAK: There are always storms there.

"There was a mass of powerful cumulonimbus formations on the flight path of AF447. Some of them may have been a source of significant turbulence.

IN CLEARSPEAK: There were just "huge" storms along its flight path and, as just said, the aircraft made no deviation..

"Several aircraft crossing the area before and after AF 447, at practically the same altitude, changed their route to avoid the cloud formations."

IN CLEARSPEAK: The other planes flying the same route -- the ones that didn't crash -- deviated in order to avoid the "huge" storms.

IN SHORT: All the aircraft that deviated survived; AF 447 that stayed on track, crashed.

So does anybody know who is responsible for not deviating the aircraft they were flying?

If you haven't figured it out, because we know it's complication, CEO Bourgeon gives you a clue in his Figaro interview:

(see translation of Gourgeon/Figaro interview: At issue is Mr. Gourgeon's statement that LH507 hit a weather bump that induced them to increase radar sensitivity; he went on to say that maybe AF447 "wasn't lucky enough" to hit such an heads-up weather bump)

IN CLEARSPEAK: the pilots of AF447 from Rio to Paris didn't know how to use their radar and "weren't lucky enough" not to get killed. Air France will be training mentally retarded pilots who'll losing their lives until they finally learn how to use the beautiful radars we let them borrow. As for his statement "regardless of whether this was the cause of the loss, we have to study all factors and upgrade the processes and procedures," you have to admit that Mr. Gourgeon doesn't talk that way when it comes to the pitot tubes -- because, as everybody knows, the pitot tubes are not, cannot be, and have been prohibited from being, the cause of the loss of AF447.

There you have it: it's all wrapped up! The plane creasehd because BEA and Air France speak with one voice: the aircraft stuck to its route on the flight plan straight into the "very big huge storms" described by Mr. Feldzer.

But is it really the case?

Is it the "established fact" the BEA says it is?

Page 13 of the BEA report show a map indicating transmission times for ACARS messages -- at 10 minute intervals as confirmed on page25.

AT 0200UTC, the aircrafte has not reached "ORARO". At 0210, it has passed ORARO but not reached TASIL.

On page 69, the BEA mentions LH507 that was about 20 minutes ahead of AF447 at the same altitude on the same route. That flight deviated "about 10 nm to the west" in order to avoid an area near ORARO that gave radar echos. Obviously, the Lufthansa B747 was smart enough to use its radar -- and therefore survived. It survived by deviating only 10nm west of the ORARO area. Think about it.

So what did AF447 do "about 20 minutes" later in the same ORARO region, i.e. between 0200 and 0210UTC?

"The flight followed the route in the flight plan," says BEA. End of story.

But before being as certain as the BEA is, you still need two things:

1. The BEA would need a continuous plot of the aircraft's positions, not a set of positions at 10-minute intervals.

2. It would have to be true.

Because, when you monitor somebody every 10 minutes, nothing proves that person's position during the nine unmonitored minutes in between. So, as Mr. De La Palice might have said, throughout each of the nine-minute intervals during which positions were not transmitted, those positions are unknown.

Thus, regardless of the BEA's somewhat hasty "established fact" nothing proves did not change course somewhere near ORARO betwen 0200 and 0210UTC just like LH507.

Quite the contrary: everything shows AF447 did deviate from the flight plan!

This is easy to show on a map alongside the "route (segment) in the flight plan" between ORARO and TASIL.

Between those two points, a straightline between them on a map amounts to the same thing as a direct curved line between them on a spherical globe. In effect, the distance between them is 119nm and the lateral gap between the two lines is negligible over so short a distance.

I'm letting go here because Eurocockpit has finished the job, but if anyone wants the rest, I'm just sitting here at home with no classes to teach till Sept. 1st.

txl

11th Jul 2009, 14:42

JuggleDan wrote: Thanks for the link. Too bad Google translate gives rubbish there, but I'm confident the the info shall be translated into another language soon.

As requested, I'll try to paraphrase what German magazine "Spiegel online" reported. Here's the original link:

Interner Bericht: Hohe Absturzquote bei Airbussen von Air France - SPIEGEL ONLINE - Nachrichten - Wirtschaft (http://www.spiegel.de/wirtschaft/0,1518,635583,00.html)

"High Crash Rate with Air France Airbuses", the headline claims. The report cites "secret calculations" supplied by "aviation sources". AF Airbus aircraft "crash more than average" - meaning Airbus fleet at other operators. It says AF Airbus fleet has a hull loss rate of 1,26 aircraft per one million flights. Average would be 0,3 per million. Of 19 Airbus planes that crashed since 1988, three were Air France and one Air Inter, now an AF subsidiary.

Those numbers, the report claims, add momentum to the debate about possible pilot errors being a factor with AF447. A "Figaro" interview with Gourgeon is qouted where the AF chief rejects speculations the AF447 crew might have flown right into the storm in order to save fuel and avoid delays

The "Spiegel" piece cites a three year old "internal AF report" that allegedly criticizes "insufficient security culture" at the French carrier. The report is quoted: AF is missing "a clear and objective view of achievements in aviation security" (my translation of a German translation of what was possibly a french source, so take with a grain of salt). Eight out of ten AF incidents were caused by human factor, the report is indirectly quoted, like insufficient attention, bad decision making processes and faulty Cpt/FO teamwork.

Analysis of A330/340 incidents supposedly has shown that Captains tend to show "a certain amount of over-confidence or even smugness", the report is further quoted (again, my possibly-lost-in-translation-disclaimer applies).

According to "Spiegel online", AF claims to have addressed these issues since the report was presented in June 2006. Still, AF/KLM Group Chief Jean-Cyril Spinetta is said to have told investors last week that AF is aware of its bad security record (wording by "Spiegel online", not a direct quote).

SaturnV

11th Jul 2009, 15:00

DutchBru

From this section:

1.17.1.4 Flight follow-up
The following operational information was exchanged via ACARS:
• at 22 h 51 the crew asked for and received the METAR of the Brazilian airfields of Belo Horizonte, Salvador de Bahia and Recife,
• at 0 h 31 dispatch sent the following message:
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,
• at 0 h 33 the crew asked for and received the METAR and TAF of Paris Charles de Gaulle, San Salvador and Sal Amilcar airports,
• at 0 h 57 the crew inquired about the use of the second ETOPS backup aerodrome and dispatch replied at 1 h 02
• at 1 h 13 the crew asked for and received the Dakar, Nouakchott and Natal METAR and TAF,
• the regulatory bilateral contact before entering an ETOPS zone (SALPU, estimated at 1 h 48 by the crew) took place between 1 h 17 and 1 h 19.

Note: the crew could take the option of requesting SIGMET by ACARS. This functionality was not used by the crew.

PEHowland

11th Jul 2009, 15:18

Quick question - I can't remember this being discussed here.

If the weather radar suffers a failure on the A330, would that be reported by ACARS? In other words, is the absence of any ACARS reports regarding the weather radar firm evidence that the weather radar was functioning correctly prior to the crash? Or is it feasible that the radar had failed and hence the reason for the aircraft apparently not avoiding the weather?

Graybeard

11th Jul 2009, 15:21

We don't know that anybody was conscious in the cockpit after 01:35. If they were merely asleep, they would have been awakened some time, maybe shortly, before the 02:10 ACARS report.

Did the BEA or Brazilian authorities investigate the activities of the pilots in the hours before the accident thoroughly enough to rule out fatigue?

GB

Me Myself

11th Jul 2009, 15:22

My point is that since the AF447 flight crew according to the BEA report did not ask for nor did they receive SIGMET updates by ACARS, they were disadvantaged in their awareness.

You are adressing a very valid issue here. More than often have I been the only one on board to worry about the sigmet's follow up. That isn't part of the compagny culture, although a recent document coming straight from the 777 chief pilot reminded everyone that it should be done.

Borges
I like the way you talk, you certainly don't mince your words.
The main reason why we don't get the exact aircraft's position more than every 10 minutes is because Pilot's unions are totally opposed to it. They are even allowed to disconnect the system if they feel like it. I know, we are in cloud cookoo land but it's the sad truth.
Why is that ?? Because pilots are scared management might be spying on them which is totally crazy. In short, it means that the owner of a 250 Mill $ aircraft isn't allowed to know his aircraft's exact positionwhen every truck owner in France knows exactly where his vehicule is.
Every 10 minutes means 80 NM and you will easily realize how so much more difficult it made the search and rescue operation.

TXL

You are right, a lot could be said about the compagny safety culture. To say there isn't any would be harsh but the smugness displayed by some crews is a fact and nothing is done about it.
Why is it so ?? Mainly because the upper levels of the compagny were so busy making Air France the major it's become, they didn't want Flight Op's and their very volatile pilots to rock the boat. For the last 15 years, the moto has been " Do not rock the boat and keep the pilots happy". Strike means losing customers hence losing money etc........... So, in essence we all were very happy. Compagny growing, fast and easy promotions, apple pie !!
No matter how compassionate or caring Mr Spinetta is, the sad fact remains that the words " accountable " and " responsability " have lost all meaning in the last 10 years.
What good does it do to have an audit producing the famous " Collin report " if the management and the pilots think they can go cherry picking and take what they like and leave the rest..........mainly the hurting bit.
Between 1969 and 1988 Air France didn't have any accident. Between 1988 et 2009 there's been 7 crashes. 2 frames were repaired, hence not appearing in the official statistics.
Between 1988 and 2009, Air France merged with 2 other airlines, both with their own very strong culture. At the same time the compagny grew so fast that it could barely find the pilots it needed and became therefore a lot less choosy than in the past. Bad choice.
There are however some outstanding blokes and of course, you never hear about them. These guys are totally pissed off right now and hope for some change while ploughing through. I am not holding my breath. I'm not talking about seeing the Flight Op's Vice president's head roll in the sand, what difference would it make ?? None !! As long as Mr Gourgeon doesn't decide to put his foot down and let the managers .............er............manage, we can just sit tight and wait for the next one to happen.
To be at the level of KLM or Cathay Pacific, we will need to be accident free for the next...............34 years !!! I find this a rather daunting task, given the circumstances.

Graybeard

11th Jul 2009, 15:45

Good Question, Howland.

The Collins radar on the AF330 fleet is highly monitored, and since it's an essential system, any detected failure would be transmitted via ACARS so that maintenance would be prepared to fix it.

Possible undetected failures would include:

*Heavy coating of ice on the radome - highly unlikely.

*Antenna plate coming detached from its pedestal. It is attached by clamps held by two small bolts that are safety-wired. That one is pretty rare, too.

All other functions, including antenna drive position, are monitored, and hence any failure would be reported.

Water ingestion into the honeycomb structure of the radome may cause false targets, but will not get large enough to matter at altitude, once frozen.

The pilot, of course, has to engage the Wx radar to display, and has to adjust intensity of the Wx display, mode, and tilt. The radar range is the range selected for Navigation on the display. Those are normal functions not reported by ACARS, and therefore a missing link at this point.

GB

Dr Brian Evans

11th Jul 2009, 15:46

An innocent question - please don't shoot me down.

Is it usual for a Captain to have far less A330 and SA experience than his F/O? Would there have been a human factors issue in which the Captain might have taken his rest during the critical period because he could/could not effectively exercise his seniority?

Or is it just a roster issue that the Captain acquired a more experienced crew than himself?

WhyIsThereAir

11th Jul 2009, 15:54

Did the BEA or Brazilian authorities investigate the activities of the pilots in the hours before the accident thoroughly enough to rule out fatigue?

In theory, yes. There is a section in the preliminary report describing very generally the activities of the pilots for the preceeding day or so. Whether that study was (or could have been) deep enough... ?

Me Myself

11th Jul 2009, 15:56

Would there have been a human factors issue in which the Captain might have taken his rest during the critical period because he could/could not effectively exercise his seniority?

Fear not, I'll hold my fire :))

It is common to have a less experienced Captain than his F/O. When you move from short haul to long haul you get to fly with more experienced F/O's on the type and on the network. You're not a yearling either. Usually, you will have spent 7/8 years as a long F/O before upgrading for command on short haul.
In the 447 case, the captain came from the former domestic carrier Air Inter and could only access long haul rather late in his carrier. Commenting on this would get me to shot on site so I'll pass. Thanks a bunch.
By no mean is it a problem to exercise your seniority and if he chose ( which we don't know ) to go and take his brake before the accident occured, this was entirely his decision.

BryceM

11th Jul 2009, 15:58

Two points:
1. Arbitrary start date, 1988, moves Habsheim crash into the 1988-2009 period.
2. Wikipedia page says AF had 3 fatal hull losses in 1968-1969

... so you could say: AF had 4 accidents in 1968-1989 period and 6 in the 1990-2009 period. And that this doesn't take into account the increasing size of the airline over the period.

The point is: accidents are rare enough that they may or may not tell you anything about whether safety culture of AF has improved or decayed.

I don't have an axe to grind, and I don't know anything about AF (only flown with them a few times). But for any western airline it's nearly impossible to make meaningful statements about safety culture using hull loss statistics.

There's a more technical prob/stats explanation which I won't burden you with...

Me Myself

11th Jul 2009, 16:09

... so you could say: AF had 4 accidents in 1968-1989 period and 6 in the 1990-2009 period. And that this doesn't take into account the increasing size of the airline over the period.

This is really far streched mate !! The last accident was in 1969 and nothing happened until 1988 which makes it a good 19 years.
The question that needs to be asked is :
How come we went from the horror show of the 1960's to the pretty good track record of the 70's and 80's.
I can partly answer that one. 2 of these 1960's crashes were the direct result of very poor CRM. I can remember flying with skippers who were F/O's during that period of time and you wouldn't believe the stories they had to tell.
Obviously, things were done during these 19 years and then..........well, the plot was lost.
Fast growth, if a factor, is not acceptable. AF isn't the only airline that grew fast in the last 20 years.

ArthurBorges

11th Jul 2009, 16:25

Borges...you certainly don't mince your words.I do avoid wordmincing but most of my content here is pure translation presented in normal Verdana font. I lapse into ego-Verdana only in the absence of translation output. When posting a mix of me and output, I toggle myself into italics.

That said, I'd love to understand the pilot union rationale for such stealth-mode cruising!

Lemurian

11th Jul 2009, 16:30

This is the most despicable piece of reporting I have ever seen...and radiococo and its subsidiaries euro ( !!!!) cockpit have quite a record of nastiness...They outdid themselves in terms of hateful anti BEA or AF agenda. Quite impressive, really.
I really am sorry that their so-called "work" is taken on this site more seriously than PH-KAR study or the more objective contributions of a few posters...

txl :

The "Spiegel" piece cites a three year old "internal AF report" that allegedly criticizes "insufficient security culture" at the French carrier.

Same tactics, here. Well known piece of news ( it's about the Colin report back in 2006 that audited the flight safety measures in the airlines).Gourgeon mentioned it in le "Figaro" interview of two days ago :
"... Qu'avez-vous vraiment changé depuis le très critique rapport Colin sur la sécurité aérienne ?

Je suis fier du rapport Colin, diffusé à tous les navigants de la compagnie, et qui montre que chez nous, il n'y a pas de tabous en matière de sécurité. En octobre 2005, nous avions confié à trois commandants de bord instructeurs d'Air France une mission d'analyse portant sur l'organisation et le fonctionnement de nos opérations aériennes. Depuis, il faut savoir que les recommandations de ce rapport ont été mises en œuvre dans tous les domaines : règles opérationnelles, organisation et sécurité des vols, formation des personnels navigants, exploitation et maintenance au sol."

My ranslation :
"..What have you done since the Colin report which was full of critics on flight safety (measures) ?
I am proud of the Colin Report, dispatched to all flying personels of the airline, which shows that in our company, there is no taboo as far as safety is concerned. In October 2005 we charged three training captains with a mission of analysis of the organisation and the functioning of our air operations. Since then, it should be made known that this report recommendations have been implemented in all domains : operational rules, organisation and flight safety, crew training, ground operations and maintenance...
Interview HERE (http://www.lefigaro.fr/actualite-france/2009/07/08/01016-20090708ARTFIG00504-af-447-tous-les-scenarios-du-drame-vont-etre)
As for the declaration COB Spinetta made :
" La sécurité de nos vols a été prise en défaut, il nous faut comprendre ce qui est arrivé", a-t-il ajouté. "Il nous faut comprendre pourquoi. Nous ne prétendons pas avoir tout bien fait", a dit M. Spinetta, à l'ouverture de l'assemblée générale des actionnaires d'Air France-KLM. "Il faut comprendre ce qui s'est passé, dire la vérité quelle qu'elle soit pour l'entreprise", a-t-il ajouté. "
or :
"the safety of our flights has been caught out. We have to understand what happened...We have to understand why. We don't pretend we've done everything right,said Mr Spinetta on the opening of the AF/KL AG...We have to understand what happened, tell the truth, whatever it is, for the airline..."
Interview Here (http://tf1.lci.fr/infos/economie/entreprises/0,,4469196,00-spinetta-un-echec-pour-air-france-.html)

That's not quite what you're so keen on publishing :

Accoring to "Spiegel online", AF claims to have addressed these issues since the report was presented in June 2006. Still, AF/KLM Group Chief Jean-Cyril Spinetta is said to have told investors last week that AF is aware of its bad security record (wording by "Spiegel online", not a direct quote).
I'm glad that some people know the quality of journalism from der Spiegel :
I guess you know Der Spiegel. It has broken many big stories but its track record for accuracy in journalism is pretty sloppy.
Thanks, ArthurBorges.
On the other hand,

For starters, the AF/Air Inter merger was, for all legal purposes, the purchase of state-owned AF by privately-owned Air Inter: Air France is just a registered trademark.
is not correct.Air Inter came into AF's basket when UTA was merged with AF. The Air Inter shares UTA brought made AF the main shareholder.
As for the financial manipulation, just replace" Air Inter" with "UTA". It's true.

I just realised that a few posts have gone through while I was doing my research.
I don't agree with everything Me Myself has written but there is definitely some truth behind his words. Some of what he wrote can explain a lot on the Alter/Radiococo/Eurocockpit attitude (still a despicable attitude, though) and if we scratch the surface a bit more, we could find that these same guys wear a heavy load on the responsibility. If Me Myself is who I think he is, he could have a lot to tell.
Me, I'm callously out of that sort of discussion.